Foam Prepared From Nanoemulsions And Uses

ABSTRACT

The present invention provides a foamable composition for administration to the skin, body surface, body cavity or mucosal surface, e.g., the mucosa of the nose, mouth, eye, ear, respiratory system, vagina or rectum, and methods of using such a composition to treat, alleviate, or prevent a disorder of the skin, body cavity, or mucosal surface. The foamable oil in water nano emulsion composition includes: (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent selected from (i) a non-ionic surfactant, (ii) an ionic surfactant, or (iii) a polymeric agent; and (c) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition, water and optional ingredients. Upon release from an aerosol container, the foamable composition forms and expanded foam suitable for topical administration.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is continuation of and claims benefit of priority to U.S. application Ser. No. 11/975,621, filed on Oct. 19, 2007, which is a continuation-in-part application of co-pending U.S. patent application Ser. No. 11/389,742, filed on Mar. 27, 2006, which (i) is a continuation-in-part of Ser. No. 10/911,367, filed on Aug. 4, 2004, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/492,385, filed on Aug. 4, 2003; (ii) claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/717,058, filed Sep. 14, 2005 and (iii) is a continuation-in-part of Ser. No. 10/532,618, filed on Dec. 22, 2005, which is a continuation-in-part of PCT/IB03/05527, filed on Oct. 24, 2003, which claims priority to U.S. Provisional Application No. 60/429,546, filed on Nov. 29, 2002 and Israeli Application No. 152486, filed on Oct. 25, 2002, all of which are incorporated in their entirety by reference.

BACKGROUND

Foams and, in particular, foam emulsions are complex dispersion systems which do not form under all circumstances. Slight shifts in foam emulsion composition, such as by the addition of active ingredients, may destabilize the foam.

Micro emulsions and nano emulsion can be monophasic, transparent (or slightly translucent) dispersions of oil and water. Unlike conventional emulsions, micro emulsions and nano emulsion can be thermodynamically stable, making them a favorable vehicle for pharmaceutical compositions, which have to maintain stability for long periods of time. Micro emulsions are sometimes said to be misleadingly called micro emulsions since they can form clear solutions devoid of the opaque color of regular emulsions. Micro emulsions can be oil external, water external and middle phase. Nano emulsions in contrast can be very fine oil in water dispersions. Droplet diameters can be as low as smaller than 100 nm. They can be in a metastable state and their structure can depend on the system history. They can be very fragile systems and can therefore be problematic in trying to formulate pharmaceutical and cosmetic compositions. If destabilized they can become opaque or exhibit creaming. On the other hand they can provide useful applications in skin care in that they may exhibit good textural and sensural properties due to the very fine droplet or globule size. Likewise for similar reasons they may provide more rapid penetration than conventional emulsions and can offer hydrating capabilities.

Foams are very complex and sensitive systems and are not formed at will. Mere addition of basic ingredients like oil, water, surfactant and propellant is far from sufficient to produce foams of quality that are homogenous, stable, breakable upon mechanical force and can be used to provide a shelf stable pharmaceutical or cosmetic composition. Small deviations may lead to foam collapse. Much consideration needs to be given to facilitate the introduction of an active agent, such as examining compatibility and non reactivity with the various excipients and container and determining shelf life chemical stability. All these considerations become a greater and more non obvious challenge when trying to formulate a foamable nano-emulsion composition, which demands the symbiosis and compatibility of a complex, sensitive system with a fragile and metastable system to produce a homogenous, stable, breakable shelf stable nano foam. Moreover, nano droplets can be sterilized by filtration.

Storage triacylglycerols (TAG) in plant seeds are present in small discrete intracellular organelles ranging from 1 to 2 μm, which are called oil-bodies. An oil body has a matrix of TAG, which is surrounded by phospholipids (PL) and alkaline proteins, termed oleosins. Oleosins are highly lipophilic proteins, are expressed at high levels in many seeds and are specifically targeted to oil-bodies. Oil-bodies are abundant in plant seeds and are among the simplest organelles present in eukaryotes. They are remarkably stable both inside the cells and in isolated preparations.

Oil bodies are also termed in the literature as “oleosomes”, “lipid bodies” and “spherosomes”.

SUMMARY

The present invention relates to foamable compositions comprising oil in water nano emulsions which produce foam having an improved bubble size compared to the foam produced form a regular oil in water emulsion; to methods of treating, alleviating or preventing a disorder of the skin, body cavity or mucosal surface using the foamable compositions; and to methods of producing a foam having an improved bubble size.

In one aspect, the present invention provides a foamable oil in water nano emulsion composition comprising: (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of (i) a non-ionic surfactant, (ii) an ionic surfactant, and (iii) a polymeric agent; (c) water; and (d) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition, wherein the oil, stabilizer and water are selected to provide a composition that is substantially homogenous and resistant to aging; wherein the composition is contained in a pressurized container is substantially flowable and provides a breakable foam upon release, which is thermally stable, yet breaks under sheer force; and wherein the bubble size of the resultant foam is significantly greater than the bubble size of the resultant foam from a composition with the same ingredients which has not been subject to nano processing.

In another aspect, the present invention provides a foamable oil in water nano emulsion composition comprising: (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of (i) a non-ionic surfactant, (ii) an ionic surfactant, and (iii) a polymeric agent; (c) water; and (d) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition, wherein the oil, stabilizer and water are selected to provide a composition that is substantially homogenous and resistant to aging and wherein the viscosity of the nano emulsion is substantially reduced than the viscosity of the a macro emulsion having substaintially the same composition; wherein the composition is contained in a pressurized container is substantially flowable and provides a breakable foam upon release, which is thermally stable, yet breaks under sheer forcea; and wherein the bubble size of the resultant foam is significantly greater than the bubble size of the resultant foam from a composition with the same ingredients which has not been subject to nano processing.

In yet another aspect, the present invention provides a foamable oil in water nano emulsion composition comprising: (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of (i) a non-ionic surfactant, (ii) an ionic surfactant, and (iii) a polymeric agent; (c) water; and (d) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition, wherein the oil, stabilizer and water are selected to provide a composition that is substantially homogenous and resistant to aging; wherein the composition prior to addition of propellant is translucent with a blue tint; wherein if the composition is contained in a pressurized container and further comprises a liquefied hydrocarbon gas propellant at a concentration of about 3% to about 35% by weight of the total composition it is substantially flowable and provides a breakable foam upon release, which is thermally stable, yet breaks under sheer force; and wherein the bubble size of the resultant foam is significantly greater than the bubble size of the resultant foam from a composition with the same ingredients which has not been subject to nano processing.

In one aspect there is provided a foamable oil in water nano emulsion, composition containing small oil globules including an oil globule system, selected from the group consisting of oil bodies and sub-micron oil globules, about 0.1% to about 5% by weight of at least one stabilizing agent selected from the group consisting of a non-ionic surfactant having an HLB value between 9 and 16, an ionic surfactant, and a polymeric agent water, as well as a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition.

According to further embodiments of the foamable composition of present invention, the oil globule system consists of oil bodies and the stabilizing agent consists of a polymeric agent.

According to still further embodiments of the foamable composition of present invention, the oil globule system consists of oil bodies and the stabilizing agent consists of an ionic surfactant.

According to yet further embodiments of the present invention the surface-active agent is a phospholipid.

According to still further embodiments of the present invention, the oil bodies are discrete oleaginous particles ranging from about 1 to about 3 μm in dimension. Oil bodies contain triacylclycerols (TAG), surrounded by phospholipids (PL) and oleosins.

According to further embodiments of the present invention, the phospholipids are selected from the group consisting of phosphatidylethanolamine, phosphatidylcholine, lecithin, phosphatidylserine, phosphatidylglycerol and phosphatidylinositol.

According to still further embodiments of the present invention, the oleosins are highly lipophilic small proteins of about 25 to 26 kD.

In one or more embodiments, the oil bodies are derived from the seeds of a plant, selected from the group consisting of almond (Prunus dulcis), anise (Pimpinella anisum), avocado (Persea spp.), beach nut (Fagus sylvatica), borage (also known as evening primrose) (Boragio officinalis), Brazil nut (Bertholetia excelsa), candle nut (Aleuritis tiglium), carapa (Carapa guineensis), cashew nut (Ancardium occidentale), castor (Ricinus communis), coconut (Cocus nucifera), coriander (Coriandrum sativum), cottonseed (Gossypium spp.), crambe (Crambe abyssinica), Crepis alpina, croton (Croton tiglium), Cuphea spp., dill (Anethum gravealis), Euphorbia lagascae, Dimorphoteca pluvialis, false flax (Camolina sativa), fennel (Foeniculum vulgaris), groundnut (Arachis hypogaea), hazelnut (coryllus avellana), hemp (Cannabis sativa), honesty plant (lunnaria annua), jojoba (Simmiondsia chinensis), kapok fruit (Ceiba pentandra), kukui nut (Aleuritis moluccana), Lesquerella spp., linseed/flax (Linum usitatissimum), macademia nut (Macademia spp.), maize (Zea mays), meadow foam (Limnanthes alba), mustard (Brassica spp. and Sinapis alba), oil palm (Elaeis guineeis), oiticia (Licania rigida), paw paw (Assimina triloba), pecan (Juglandaceae ssp.), perilla (Perilla futescens), physic nut (Gairopha curcas), pilinut (Canariuim ovatum), pine nut (pine spp.), pistachio (Pistachia vera), pongam (Bongamin glabra), poppy seed (Papaver soniferum), rapeseed (Brassica spp.), safflower (Carthamus tinctorius), sesame seed (Sesamum indicum), soybean (Glycine max), squash (Cucurbita maxima), sal tree (Shorea rubusha), Stokes aster (Stokesia laevis), sunflower (Helianthus annuus), tukuma (Astocarya spp.), tung nut (Aleuritis cordata), and vernolnia (Verzonia galamensis).

According to a further embodiment of the foamable composition, the foamable composition further includes about 0.1% to about 5% by weight of a foam adjuvant selected from the group consisting of a fatty alcohol having 15 or more carbons in their carbon chain, a fatty acid having 16 or more carbons in their carbon chain, fatty alcohols derived from beeswax and including a mixture of alcohols, a majority of which has at least 20 carbon atoms in their carbon chain, a fatty alcohol having at least one double bond, a fatty acid having at least one double bond, a branched fatty alcohol, a branched fatty acid, and a fatty acid substituted with a hydroxyl group and mixtures thereof.

According to further embodiments of the present invention, the foamable composition is substantially alcohol-free.

According to still further embodiments of the present invention, the concentration range of oil globules is selected from the group of (i) about 0.05% and about 2% and about 5%, (ii) about 2% (iii) about 5% and about 12%, and (iv) about 12% and about 24%.

According to further embodiments of the present invention, the polymeric agent is selected from the group consisting of a water-soluble cellulose ether and naturally-occurring polymeric material.

According to still further embodiments of the present invention, the water-soluble cellulose ether is selected from the group consisting of methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose (Methocel), hydroxyethyl cellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, hydroxyethylcarboxymethylcellulose, carboxymethylcellulose, carboxymethylhydroxyethylcellulose, xanthan gum, guar gum, carrageenin gum, locust bean gum and tragacanth gum.

According to yet further embodiments of the present invention, the foamable composition further includes at least one therapeutic agent.

According to further embodiments of the present invention, the therapeutic agent is selected from the group consisting of an anti-infective, an antibiotic, an antibacterial agent, an antifungal agent, an antiviral agent, an antiparasitic agent, an steroidal anti-inflammatory agent, an immunosuppressive agent, an immunomodulator, an immunoregulating agent, a hormonal agent, vitamin A, a vitamin A derivative, vitamin B, a vitamin B derivative, vitamin C, a vitamin C derivative, vitamin D, a vitamin D derivative, vitamin E, a vitamin E derivative, vitamin F, a vitamin F derivative, vitamin K, a vitamin K derivative, a wound healing agent, a disinfectant, an anesthetic, an antiallergic agent, an alpha hydroxyl acid, lactic acid, glycolic acid, a beta-hydroxy acid, a protein, a peptide, a neuropeptide, a allergen, an immunogenic substance, a haptene, an oxidizing agent, an antioxidant, a dicarboxylic acid, azelaic acid, sebacic acid, adipic acid, fumaric acid, a retinoid, an antiproliferative agent, an anticancer agent, a photodynamic therapy agent, an anti-wrinkle agent, a radical scavenger, a metal oxide (e.g., titanium dioxide, zinc oxide, zirconium oxide, iron oxide, silicone oxide, an anti wrinkle agent, a skin whitening agent, a skin protective agent, a masking agent, an anti-wart agent, a refatting agent, a lubricating agent and mixtures thereof).

According to still further embodiments of the present invention, the therapeutic agent is selected from the components of the oil bodies or sub-micron oil globules.

According to further embodiments of the present invention, the therapeutic agent is suitable to treat a disorder selected from the group consisting of dermatological disorder, a cosmetic disorder, a gynecological disorder, a disorder of a body cavity, wound and burn.

In a further aspect, the present invention provides methods of treating, alleviating or preventing a disorder of the skin, body cavity or mucosal surface using the foamable compositions described herein.

In one aspect, the present invention provides a method of treating, alleviating or preventing a disorder of the skin, body cavity or mucosal surface, wherein said disorder involves insufficient hydration of skin or a mucosal surface as one of its etiological factors, comprising: administering topically to a subject having said disorder, a foamed composition comprising: (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of (i) a non-ionic surfactant, (ii) an ionic surfactant, and (iii) a polymeric agent; (c) water; and (d) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition, wherein the oil, stabilizer and water are selected to provide a composition that is substantially homogenous and resistant to aging and wherein the viscosity of the pre foam formulation remains substantially high after it has been subject to nano processing; wherein the composition is contained in a pressurized container is substantially flowable and provides a breakable foam upon release, which is thermally stable, yet breaks under sheer force; and wherein the bubble size of the resultant foam is significantly greater than the bubble size of the resultant foam from a composition with the same ingredients which has not been subject to nano processing.

According to a further embodiment of the present invention, there is provided a method of treating, alleviating or preventing a disorder of the skin, body cavity or mucosal surface, wherein the disorder involves insufficient hydration of skin or a mucosal surface as one of its etiological factors. The method includes administering topically to a subject having the disorder, a foamed composition containing (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of (i) a non-ionic surfactant, (ii) an ionic surfactant, and (iii) a polymeric agent; (c) water; and (d) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition.

According to a further embodiment of the method, the composition further includes an active agent effective to treat a disorder, and wherein the disorder is selected from the group consisting of a vaginal disorder, a vulvar disorder, an anal disorder, a disorder of a body cavity, an ear disorder, a disorder of the nose, a disorder of the respiratory system, a bacterial infection, fungal infection, viral infection, dermatosis, dermatitis, parasitic infections, disorders of hair follicles and sebaceous glands, scaling papular diseases, benign tumors, malignant tumors, reactions to sunlight, bullous diseases, pigmentation disorders, disorders of cornification, pressure sores, disorders of sweating, inflammatory reactions, xerosis, ichthyosis, allergy, burn, wound, cut, chlamydia infection, gonorrhea infection, hepatitis B, herpes, HIV/AIDS, human papillomavirus (HPV), genital warts, bacterial vaginosis, candidiasis, chancroid, granuloma Inguinale, lymphogranloma venereum, mucopurulent cervicitis (MPC), molluscum contagiosum, nongonococcal urethritis (NGU), trichomoniasis, vulvar disorders, vulvodynia, vulvar pain, yeast infection, vulvar dystrophy, vulvar intraepithelial neoplasia (VIN), contact dermatitis, osteoarthritis, joint pain, hormonal disorder, pelvic inflammation, endometritis, salpingitis, oophoritis, genital cancer, cancer of the cervix, cancer of the vulva, cancer of the vagina, vaginal dryness, dyspareunia, anal and rectal disease, anal abscess/fistula, anal cancer, anal fissure, anal warts, Crohn's disease, hemorrhoids, anal itch, pruritus ani, fecal incontinence, constipation, polyps of the colon and rectum.

According to a further embodiment of the present invention, there is provided a method to promote the penetration of an active agent into the surface layers of the skin and mucosal membranes. The method includes applying a foamable composition to the surface layers of a skin or mucosal membrane the foamable composition, comprising (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of (i) a non-ionic surfactant, (ii) an ionic surfactant, and (iii) a polymeric agent; (c) water; and (d) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition.

According to a further embodiment of the present invention, there is provided a method of treating, alleviating or preventing a disorder of the skin, body cavity or mucosal surface, wherein said disorder involves insufficient hydration of skin or a mucosal surface as one of its etiological factors. The method includes applying a foamable composition to the surface layers of a skin, body cavity or mucosal membrane the foamable composition, comprising (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of (i) a non-ionic surfactant, (ii) an ionic surfactant, and (iii) a polymeric agent; (c) water; and (d) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition. In certain embodiments, the composition prior to addition of propellant is translucent with a blue tint.

In one aspect, the present invention provides a method of producing a foam having improved foam bubble size comprising: (i) preparing a pre foam oil in water emulsion formulation, wherein the pre foam oil comprises (a) oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent selected from the group consisting of a non-ionic surfactant, an ionic surfactant, and a polymeric agent; and (c) water; (ii) subjecting the pre foam formulation to high pressure mechanical stress to produce a nano emulsion; (iii) storing the nano emulsion in a sealed pressurized container that further comprises a liquefied hydrocarbon gas propellant at a concentration of about 3% to about 25% by weight of the total composition and having an outlet capable of releasing the pressurized product as a foam; and (iv) releasing the foam, wherein the bubble size of the resultant foam is significantly greater than the bubble size of a resultant foam from the pre foam oil in water emulsion formulation stored in a sealed pressurized container that further comprises a liquefied hydrocarbon gas propellant at a concentration of about 3% to about 25% by weight of the total composition and having an outlet capable of releasing the pressurized product as a foam.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows pictures of a sample section of the foam produced from composition 13 of Example 9 before nano processing.

FIG. 1B shows pictures of a sample section of the foam produced from composition 13 of Example 9 after 6 cycles of nano processing.

FIG. 2A shows pictures of a sample section of the foam produced from composition 11 of Example 8 before nano processing.

FIG. 2B shows pictures of a sample section of the foam produced from composition 11 of Example 8 after 6 cycles of nano processing.

FIG. 3A shows pictures of a sample section of the foam produced from composition 7 of Example 7 before nano processing.

FIG. 3B shows pictures of a sample section of the foam produced from composition 10 of Example 7 after 6 cycles of nano processing.

FIG. 4A shows pictures of a sample section of the foam produced from composition 14 of Example 9 before nano processing.

FIG. 4B shows pictures of a sample section of the foam produced from composition 14 of Example 9 after 6 cycles of nano processing.

FIG. 5A shows pictures of a sample section of the foam produced from composition 15 of Example 9 before nano processing, which foam comprises propellant having 50% more pressure than that of the foam as shown in FIG. 5B.

FIG. 5B shows pictures of a sample section of the foam produced from composition 15 of Example 9 before nano processing.

FIG. 5C shows pictures of a sample section of the foam produced from composition 15 of Example 9 after 6 cycles of nano processing.

DETAILED DESCRIPTION

The present invention provides a foamable oil in water nano emulsion, composition including small oil globules. As used herein, the terms droplets, globules and particles, when referencing an emulsion, are used interchangeably. All % values are provided on a weight (w/w) basis.

According to one or more embodiments of the present invention, the foamable oil in water nano emulsion composition is intended for administration to the skin, a body surface, a body cavity or mucosal surface, e.g., the mucosa of the nose, mouth, eye, ear, respiratory system, vagina or rectum (severally and interchangeably termed herein “target site”).

In an embodiment there is provided a foamable oil in water nano emulsion composition comprising:

-   -   (a) A nano oil globule system, comprising substantially of         sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent, selected from the group consisting of         -   i. a non-ionic surfactant,         -   ii. an ionic surfactant, and         -   iii. a polymeric agent;     -   (c) water; and     -   (d) a liquefied or compressed gas propellant at a concentration         of about 3% to about 25% by weight of the total composition         wherein the oil, stabilizer and water are selected to provide a         composition that is substantially homogenous and resistant to         aging;         wherein the composition is contained in a pressurized container         is substantially flowable and provides a breakable foam upon         release, which is thermally stable, yet breaks under sheer         force; and         wherein the bubble size of the resultant foam is significantly         greater than the bubble size of the resultant foam from a         composition with the same ingredients which has not been subject         to nano processing.

In another embodiment the oil globule system consists of oil globules with an average diameter size in the range of about 1000 nanometers to about 10 nanometers; and the stabilizing agent consists of a polymeric agent.

In an embodiment there is provided a foamable oil in water nano emulsion composition comprising a non-ionic surfactant having an HLB value between 9 and 16; and/or an ionic surfactant.

In another embodiment the oil globules are discrete particles with the majority having a size ranging from about 300 to about 20 nanometers in at least one dimension.

In another embodiment the oil globule system consists of sub-micron oil globules; and the stabilizing agent consists of a surfactant, having an HLB value or a mean HLB value between 9 and 16.

In a further embodiment the ratio of surfactant to oil is high being in the range of the order of about 1:1 to about 1:10

In another embodiment the sub-micron oil globules contain at least one organic carrier selected from the group consisting of a hydrophobic organic carrier, a polar solvent, an emollient and mixtures thereof.

In a further embodiment said submicron oil globules are about 50% to about 100% of the composition.

In another embodiment the sub-micron oil globules have a number-average size range, selected from (i) 40 nm to 1,000 nm. (ii) 40 nm to 500 nm; (iii) 40 nm to 200 nm; (iv) 40 nm to 100 nm (v) less than 500 nm; (vi) less than 200 nm; and (vii) less than 100 nm.

In an embodiment the sub-micron oil globules are produced by high sheer homogenization.

In an embodiment there is provided a foamable oil in water nano emulsion composition further comprising about 0.1% to about 5% by weight of a foam adjuvant selected from the group consisting of a fatty alcohol having 15 or more carbons in their carbon chain; a fatty acid having 16 or more carbons in their carbon chain; fatty alcohols derived from beeswax and including a mixture of alcohols, a majority of which has at least 20 carbon atoms in their carbon chain; a fatty alcohol having at least one double bond; a fatty acid having at least one double bond; a branched fatty alcohol; a branched fatty acid; and a fatty acid substituted with a hydroxyl group and mixtures thereof.

In an embodiment said foamable composition is substantially alcohol-free.

In an embodiment there is provided a foamable oil in water nano emulsion composition further containing at least one therapeutic agent.

In an embodiment the therapeutic agent is selected from the group consisting of an anti-infective, an antibiotic, an antibacterial agent, an antifungal agent, an antiviral agent, an antiparasitic agent, an steroidal antiinflammatory agent, an immunosuppressive agent, an immunomodulator, an immunoregulating agent, a hormonal agent, vitamin A, a vitamin A derivative, vitamin B, a vitamin B derivative, vitamin C, a vitamin C derivative, vitamin D, a vitamin D derivative, vitamin E, a vitamin E derivative, vitamin F, a vitamin F derivative, vitamin K, a vitamin K derivative, a wound healing agent, a disinfectant, an anesthetic, an antiallergic agent, an alpha hydroxyl acid, lactic acid, glycolic acid, a beta-hydroxy acid, a protein, a peptide, a neuropeptide, a allergen, an immunogenic substance, a haptene, an oxidizing agent, an antioxidant, a dicarboxylic acid, azelaic acid, sebacic acid, adipic acid, fumaric acid, a retinoid, an antiproliferative agent, an anticancer agent, a photodynamic therapy agent, an anti-wrinkle agent, a radical scavenger, a metal oxide (e.g., titanium dioxide, zinc oxide, zirconium oxide, iron oxide), silicone oxide, an anti wrinkle agent, a skin whitening agent, a skin protective agent, a masking agent, an anti-wart agent, a refatting agent, a lubricating agent and mixtures thereof.

In an embodiment the therapeutic agent is suitable to treat a disorder, selected from a dermatological disorder, a cosmetic disorder, a gynecological disorder, a disorder of a body cavity, wound and burn.

In an embodiment there is provided a foamable oil in water nano emulsion composition wherein the HLB or mean HLB value of said non-ionic surfactant is between about 2 and about 9.

In an embodiment the stabilizing agent is a polymeric agent selected from the group consisting of a water-soluble cellulose ether naturally-occurring polymeric material, microcrystalline cellulose, hydrophobically-modified ethoxylated urethane, and a carbomer.

In an embodiment the water-soluble cellulose ether is selected from the group consisting of methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose (Methocel), hydroxyethyl cellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, hydroxyethylcarboxymethylcellulose, carboxymethylcellulose, carboxymethylhydroxyethylcellulose, xanthan gum, guar gum, carrageenin gum, locust bean gum and tragacanth gum.

In an embodiment the surfactant is selected from the group consisting of steareth 2, steareth 21, ceteth-20, span 80, behenyl alcohol, glyceryl monostearate, PEG 40 stearate, polyoxyl 100 monostearate, methyl glucose seasquit stearate and polysorbate 80.

In an embodiment there is provided a foamable oil in water nano emulsion composition wherein the density of the foam is selected from the group consisting of (1) less than 0.12 g/mL; (2) the range between 0.02 and 0.12; (3) the range between 0.04 and 0.10; (4) the range between 0.06 and 0.10.

In an embodiment there is provided a foamable oil in water nano emulsion composition comprising:

-   -   (a) A nano oil globule system, comprising substantially of         sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent, selected from the group consisting of         -   i. a non-ionic surfactant,         -   ii. an ionic surfactant, and         -   iii. a polymeric agent;     -   (c) water; and     -   (d) a liquefied or compressed gas propellant at a concentration         of about 3% to about 25% by weight of the total composition         wherein the oil, stabilizer and water are selected to provide a         composition that is substantially homogenous and resistant to         aging and wherein the viscosity of the pre foam formulation is         substantially reduced after it has been subject to nano         processing;         wherein the composition is contained in a pressurized container         is substantially flowable and provides a breakable foam upon         release, which is thermally stable, yet breaks under sheer         force; and         wherein the bubble size of the resultant foam is significantly         greater than the bubble size of the resultant foam from a         composition with the same ingredients which has not been subject         to nano processing.

In an embodiment there is provided a foamable oil in water nano emulsion composition wherein the viscosity is selected from the group consisting of (1) between about 6000 cP and about 4000 cP (2) between about 4000 cP and about 2000 cP (3) between about 2000 cP and about 500 cP (4) between about 500 cP and about 1 cP.

In an embodiment the viscosity is preferably between about 500 cP and about 1 cP and the foam is of good or excellent quality.

In another embodiment the viscosity is above 20,000 cP.

In another embodiment the polymeric agent is a carbomer. In another embodiment the carbomer is the sole polymeric agent.

In a further embodiment the carbomer substantially contributes to the viscosity and exhibits resistant to viscosity reduction on nano processing

In a further embodiment there is provided a foamable oil in water nano emulsion composition comprising:

-   -   (a) A nano oil globule system, comprising substantially of         sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent comprising a carbomer polymeric agent, and a second         stabilizing agent selected from the group consisting of         -   i. a non-ionic surfactant,         -   ii. an ionic surfactant, and         -   iii. a polymeric agent;     -   (c) water; and     -   (d) a liquefied or compressed gas propellant at a concentration         of about 3% to about 25% by weight of the total composition         wherein the oil, stabilizer and water are selected to provide a         composition that is substantially homogenous and resistant to         aging and wherein the viscosity of the pre foam formulation         remains substantially high after it has been subject to nano         processing;         wherein the composition is contained in a pressurized container         is substantially flowable and provides a breakable foam upon         release, which is thermally stable, yet breaks under sheer         force; and         wherein the bubble size of the resultant foam is significantly         greater than the bubble size of the resultant foam from a         composition with the same ingredients which has not been subject         to nano processing.

In a still further embodiment there is provided a foamable oil in water nano emulsion composition comprising:

-   -   (a) a nano oil globule system, comprising substantially of         sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent, selected from the group consisting of         -   i. a non-ionic surfactant,         -   ii. an ionic surfactant, and         -   iii. a polymeric agent; and     -   (c) water;         wherein the oil, stabilizer and water are selected to provide a         composition that is substantially homogenous and resistant to         aging;         wherein the composition prior to addition of propellant is         translucent with a blue tint;         wherein if the composition is contained in a pressurized         container and further comprises a liquefied hydrocarbon gas         propellant at a concentration of about 3% to about 35% by weight         of the total composition it is substantially flowable and         provides a breakable foam upon release, which is thermally         stable, yet breaks under sheer force; and         wherein the bubble size of the resultant foam is significantly         greater than the bubble size of the resultant foam from a         composition with the same ingredients which has not been subject         to nano processing.

In another embodiment there is provided a method of treating, alleviating or preventing a disorder of the skin, body cavity or mucosal surface, wherein said disorder involves insufficient hydration of skin or a mucosal surface as one of its etiological factors, comprising:

-   -   administering topically to a subject having said disorder, a         foamed composition comprising:     -   (a) a nano oil globule system, comprising substantially of         sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent, selected from the group consisting of         -   i. a non-ionic surfactant,         -   ii. an ionic surfactant, and         -   iii. a polymeric agent;     -   (c) water; and     -   (d) a liquefied or compressed gas propellant at a concentration         of about 3% to about 25% by weight of the total composition         wherein the oil, stabilizer and water are selected to provide a         composition that is substantially homogenous and resistant to         aging;         wherein the composition is contained in a pressurized container         is substantially flowable and provides a breakable foam upon         release, which is thermally stable, yet breaks under sheer         force; and         wherein the bubble size of the resultant foam is significantly         greater than the bubble size of the resultant foam from a         composition with the same ingredients which has not been subject         to nano processing.

In an additional embodiment the composition further comprises an active agent effective to treat a disorder and wherein the disorder is selected from the group consisting of a vaginal disorder, a vulvar disorder, an anal disorder, a disorder of a body cavity, an ear disorder, a disorder of the nose, a disorder of the respiratory system, a bacterial infection, fungal infection, viral infection, dermatosis, dermatitis, parasitic infections, disorders of hair follicles and sebaceous glands, scaling papular diseases, benign tumors, malignant tumors, reactions to sunlight, bullous diseases, pigmentation disorders, disorders of cornification, pressure sores, disorders of sweating, inflammatory reactions, xerosis, ichthyosis, allergy, burn, wound, cut, chlamydia infection, gonorrhea infection, hepatitis B, herpes, HIV/AIDS, human papillomavirus (HPV), genital warts, bacterial vaginosis, candidiasis, chancroid, granuloma Inguinale, lymphogranloma venereum, mucopurulent cervicitis (MPC), molluscum contagiosum, nongonococcal urethritis (NGU), trichomoniasis, vulvar disorders, vulvodynia, vulvar pain, yeast infection, vulvar dystrophy, vulvar intraepithelial neoplasia (VIN), contact dermatitis, osteoarthritis, joint pain, hormonal disorder, pelvic inflammation, endometritis, salpingitis, oophoritis, genital cancer, cancer of the cervix, cancer of the vulva, cancer of the vagina, vaginal dryness, dyspareunia, anal and rectal disease, anal abscess/fistula, anal cancer, anal fissure, anal warts, Crohn's disease, hemorrhoids, anal itch, pruritus ani, fecal incontinence, constipation, polyps of the colon and rectum.

In one or more embodiments there is provided a method of promoting the penetration of an active agent into the surface layers of the skin and mucosal membranes, comprising: apply a foamable composition to the surface layers of a stem or mucosal membrane, the foamable composition comprising:

-   -   (a) a nano oil globule system, comprising substantially of         sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent, selected from the group consisting of         -   i. a non-ionic surfactant,         -   ii. an ionic surfactant, and         -   iii. a polymeric agent;     -   (c) water; and     -   (d) a liquefied or compressed gas propellant at a concentration         of about 3% to about 25% by weight of the total composition         wherein the oil, stabilizer and water are selected to provide a         composition that is substantially homogenous and resistant to         aging;         wherein the composition is contained in a pressurized container         is substantially flowable and provides a breakable foam upon         release, which is thermally stable, yet breaks under sheer         force; and         wherein the bubble size of the resultant foam is significantly         greater than the bubble size of the resultant foam from a         composition with the same ingredients which has not been subject         to nano processing.

In a further embodiment of the method of promoting penetration the active agent is selected from the group consisting of an anti-infective, an antibiotic, an antibacterial agent, an antifungal agent, an antiviral agent, an antiparasitic agent, an steroidal antiinflammatory agent, an immunosuppressive agent, an immunomodulator, an immunoregulating agent, a hormonal agent, vitamin A, a vitamin A derivative, vitamin B, a vitamin B derivative, vitamin C, a vitamin C derivative, vitamin D, a vitamin D derivative, vitamin E, a vitamin E derivative, vitamin F, a vitamin F derivative, vitamin K, a vitamin K derivative, a wound healing agent, a disinfectant, an anesthetic, an antiallergic agent, an alpha hydroxyl acid, lactic acid, glycolic acid, a beta-hydroxy acid, a protein, a peptide, a neuropeptide, a allergen, an immunogenic substance, a haptene, an oxidizing agent, an antioxidant, a dicarboxylic acid, azelaic acid, sebacic acid, adipic acid, fumaric acid, a retinoid, an antiproliferative agent, an anticancer agent, a photodynamic therapy agent, an anti-wrinkle agent, a radical scavenger, a metal oxide (e.g., titanium dioxide, zinc oxide, zirconium oxide, iron oxide), silicone oxide, an anti wrinkle agent, a skin whitening agent, a skin protective agent, a masking agent, an anti-wart agent and a refatting agent.

In a further embodiment there is provided a method of treating, alleviating or preventing a disorder of the skin, body cavity or mucosal surface, wherein said disorder involves insufficient hydration of skin or a mucosal surface as one of its etiological factors, comprising:

-   -   administering topically to a subject having said disorder, a         foamed composition comprising:     -   (a) a nano oil globule system, comprising substantially of         sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent, selected from the group consisting of         -   i. a non-ionic surfactant,         -   ii. an ionic surfactant, and         -   iii. a polymeric agent; and     -   (c) water;         wherein the oil, stabilizer and water are selected to provide a         composition that is substantially homogenous and resistant to         aging;         wherein the composition prior to addition of propellant is         translucent with a blue tint;         wherein if the composition is contained in a pressurized         container and further comprises a liquefied hydrocarbon gas         propellant at a concentration of about 3% to about 35% by weight         of the total composition it is substantially flowable and         provides a breakable foam upon release, which is thermally         stable, yet breaks under sheer force; and         wherein the bubble size of the resultant foam is significantly         greater than the bubble size of the resultant foam from a         composition with the same ingredients which has not been subject         to nano processing.

In a further embodiment of the method of treating, alleviating or preventing a disorder of the skin, body cavity or mucosal surface the composition further comprises an active agent effective to treat a disorder and wherein the disorder is selected from the group described above.

In a further embodiment there is provided a method of promoting the penetration of an active agent into the surface layers of the skin and mucosal membranes, comprising: apply a foamable composition to the surface layers of a stem or mucosal membrane, the foamable composition comprising:

-   -   (a) a nano oil globule system, comprising substantially of         sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent, selected from the group consisting of         -   i. a non-ionic surfactant,         -   ii. an ionic surfactant, and         -   iii. a polymeric agent; and     -   (c) water;         wherein the oil, stabilizer and water are selected to provide a         composition that is substantially homogenous and resistant to         aging;         wherein the composition prior to addition of propellant is         translucent with a blue tint;         wherein if the composition is contained in a pressurized         container and further comprises a liquefied hydrocarbon gas         propellant at a concentration of about 3% to about 35% by weight         of the total composition it is substantially flowable and         provides a breakable foam upon release, which is thermally         stable, yet breaks under sheer force; and         wherein the bubble size of the resultant foam is significantly         greater than the bubble size of the resultant foam from a         composition with the same ingredients which has not been subject         to nano processing.

In a further embodiment of the method of promoting the penetration of an active agent the active agent is selected from the group listed above.

In one or more other embodiments there is provided a foamable oil in water nano emulsion composition for use as a medicament or in the manufacture of a medicament.

In one or more embodiments there is also provided a method of producing a foam having improved foam bubble size comprising

-   -   i. preparing a pre foam oil in water emulsion formulation;     -   ii. subjecting the pre foam formulation to high pressure         mechanical stress to produce a nano emulsion;     -   iii. storing the nano emulsion in a sealed pressurized container         that further comprises a liquefied hydrocarbon gas propellant at         a concentration of about 3% to about 25% by weight of the total         composition and having an outlet capable of releasing the         pressurized product as a foam; and     -   iv. releasing the foam;     -   wherein the bubble size of the resultant foam is significantly         greater than the bubble size of a resultant foam from the pre         foam oil in water emulsion formulation stored in a sealed         pressurized container that further comprises a liquefied         hydrocarbon gas propellant at a concentration of about 3% to         about 25% by weight of the total composition and having an         outlet capable of releasing the pressurized product as a foam.

The foamable oil in water nano emulsion composition includes:

-   -   (a) an oil globule system selected from the group consisting of         oil bodies and sub-micron oil globules;     -   (b) about 0.1% to about 5% by weight of at least one stabilizing         agent selected from the group consisting of a non-ionic         surfactant selected from the group consisting of a non-ionic         surfactant, having an HLB value between 9 and 16, an ionic         surfactant; and a polymeric agent; and     -   (c) a liquefied or compressed gas propellant at a concentration         of about 3% to about 25% by weight of the total composition.

Water and optional ingredients are added to complete the total mass to 100%. Upon release from an aerosol container, the foamable composition forms an expanded foam suitable for topical administration.

In one or more embodiments, the oil globules are oil bodies. Oil bodies, also termed “oleosomes”, “lipid bodies” and “spherosomes”, are small discrete oleaginous particles, ranging in size from about 1 to about 3 μm along one dimension. Oil bodies consist of triacylglycerols (TAG) surrounded by phospholipids (PL) and alkaline proteins, termed oleosins.

Triacylglycerides (also termed triglycerides) are chemically defined as glycerol esters of fatty acids. The seed oil present in the oil body fraction of plant species is a mixture of various triacylglycerides, of which the exact composition depends on the plant species from which the oil is derived.

Phospolipids possess a structure that is very similar to that of the triacylglycerides except that a terminal carbon of the glycerol backbone is esterified to phosphoric acid. Substitution of the hydrogen atom of phosphatidic acid results in additional phospholipids classes, including but not limited to the following:

Substitution Phospholipid Ethanolamine Phosphatidylethanolamine Choline Phosphatidylcholine, also called lecithins Serine Phosphatidylserine Glycerol Phosphatidylglycerol Myo-inositol Phosphatidylinositol

Oleosins are highly lipophilic small proteins of about 15 to 26 kD. They are expressed at high levels in many seeds and are specifically targeted to oil-bodies. Oleosins completely cover the surface of the subcellular oil bodies.

Oil-bodies are abundant in plant seeds and are among the simplest organelles present in eukaryotes. They are remarkably stable both inside the cells and in isolated preparations.

Oil bodies are prepared from plant seeds. Exemplary plant seeds include (alphabetically) almond (Prunus dulcis); anise (Pimpinella anisum); avocado (Persea spp.); beach nut (Fagus sylvatica); borage (also known as evening primrose) (Boragio officinalis); Brazil nut (Bertholletia excelsa); candle nut (Aleuritis tiglium); carapa (Carapa guineensis); cashew nut (Ancardium occidentale); castor (Ricinus communis); coconut (Cocus nucifera); coriander (Coriandrum sativum); cottonseed (Gossypium spp.); crambe (Crambe abyssinica); Crepis alpina; croton (Croton tiglium); Cuphea spp.; dill (Anethum gravealis); Euphorbia lagascae; Dimorphoteca pluvialis; false flax (Camolina sativa); fennel (Foeniculum vulgaris); groundnut (Arachis hypogaea); hazelnut (coryllus avellana); hemp (Cannabis sativa); honesty plant (Lunnaria annua); jojoba (Simmiondsia chinensis); kapok fruit (Ceiba pentandra); kukui nut (Aleuritis moluccana); Lesquerella spp., linseed/flax (Linum usitatissimum); macademia nut (Macademia spp.); maize (Zea mays); meadow foam (Limnanthes alba); mustard (Brassica spp. and Sinapis alba); oil palm (Elaeis guineeis); oiticia (Licania rigida); paw paw (Assimina triloba); pecan (Juglandaceae spp.); perilla (Perilla frutescens); physic nut (Gairopha curcas); pilinut (Canariuim ovatum); pine nut (pine spp.); pistachio (Pistachia vera); pongam (Bongamin glabra); poppy seed (Papaver soniferum); rapeseed (Brassica spp.); safflower (Carthamus tinctorius); sesame seed (Sesamum indicum); soybean (Glycine max); squash (Cucurbita maxima); sal tree (Shorea rubusha); Stokes aster (Stokesia laevis); sunflower (Helianthus annuus); tukuma (Astocarya spp.); tung nut (Aleuritis cordata); and vernolnia (Verzonia galamensis). Isolation of oil bodies from plant sources is well known. See, for example, U.S. Pat. No. 5,650,554.

Stable artificial oil bodies can be reconstituted with triacylglycerol, phospholipid, and oleosin via sonication, as described, for example in J. T. C. Tzen, Y. Z. Cao, P. Laurent, C. Ratnayake, and A. H. C. Huang. 1993. Lipids, proteins, and structure of seed oil bodies from diverse species. Plant Physiol. 101:267-276.

The skin-beneficial effects of oil bodies include, but are not limited to (1) antioxidant effects (resulting from the presence of tocopherol and other antioxidants naturally present in the oil bodies); (2) occlusivity, as determined by improved skin barrier function and reduced trans-epidermal water loss; and (3) emolliency. Furthermore, the oil bodies building blocks—the triacylglycerides and the phospholipids—contain unsaturated or polyunsaturated fatty acids. Exemplary unsaturated fatty acids are omega-3 and omega-6 fatty acids. Other examples of such polyunsaturated fatty acids are linoleic and linolenic acid, gamma-linoleic acid (GLA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Such unsaturated fatty acids are known for their skin-conditioning and anti-inflammatory effects, which contribute to the therapeutic benefit of the present foamable composition.

Because oil bodies contain phospholipids and oleosins, which concurrently carry hydrophobic and hydrophilic moieties, they act as emulsifiers and, as a result, upon dilution with water with mild mixing, they spontaneously form an emulsion.

In one or more embodiments, the oil globules are sub-micron oil globules, i.e., oil globules, which have a number-average size of less than 1,000 nm. An emulsion, comprising sub-micron globules or nano-size globules is called sub-micron emulsion (“SME”) or microemulsion or nanoemulsion, respectively. In one or more embodiments, the oil globules have a number-average size of less than 500 nm; or less than 200 nm; or less than 100 nm. In certain embodiments, the oil globules have number-average size in the following ranges: (i) 40 nm to 1,000 nm. (ii) 40 nm to 500 nm; (iii) 40 nm to 200 nm; or (iv) 40 nm to 100 nm.

SMEs are dispersions of oil and water. With reference to conventional emulsions, SMEs are more stable, making them a favorable vehicle for pharmaceutical compositions, which have to maintain stability for long periods of time. SMEs may be used in vehicles for transporting nutraceuticals, medicaments, peptides or proteins. The decrease in size of the globules makes it possible to promote the penetration of the active agents into the surface layers of the skin and mucosal membranes.

In SMEs, the active compounds can be solubilized. The general concept of solubilization of active components and its utilization may be found in the following review articles: 1. Solans, C., Pons, R., Kunieda, H “Overview of basic aspects of microemulsions” Industrial Applications of Microemulsions, Solans, C., Kunieda, H., Eds.: Dekker, New York (1997); 66: 1-17, 2. Dungan, S. R., “Microemulsions in foods: properties and application” ibid 148-170; 3. Holmberg, K. “Quarter century progress and new horizons in microemulsions” in Micelles, Microemulsions and Monolayers, Shah, 0. Ed.; Dekker: New York (1998) 161-192; 4. Garti, N. “Microemulsions, emulsions, double emulsions and emulsions in food” in Formulation Science (proceeding from formulation forum '97 association of formulation chemists) (1998) 1, 147-219; 5. Ezrahi, S., Aserin, A. Garti, N. in Micoremulsions-fundamental wad applied aspects Kumar, P. and Mittal, K. L. Eds. Marcel Dekker, Inc. New York (1999) “Aggregation behavior in one-phase (Winsor IV) systems” 185-246; 6. Garti, N. Clement, V., Leser, M., Aserin, A. Fanun, M. “Sucrose esters microemulsions J. Molec. Liquids (1999) 80, 253-296.

In certain embodiments, the production of SMEs and nanoemulsion involves very-high sheer homogenizers. An exemplary homogenizer, suitable for producing nano-emulsions is the commercially-available “Microfluidizer®”. Microfluidizer® fluid processors are built for deagglomeration and dispersion of uniform submicron particles and creation of stable emulsions and dispersions. Microfluidizer processors overcome limitations of conventional processing technologies by utilizing high-pressure streams that collide at ultra-high velocities in precisely defined microchannels. Combined forces of shear and impact act upon products to attain uniform particle and droplet size reduction (often submicron), deagglomeration and high yield cell disruption.

Notwithstanding the above, any other very-high sheer homogenizer, capable of producing submicron particles is suitable for use in the production of a microemulsions or a nanoemulsion according to the present invention.

In additional embodiments, the SMEs form spontaneously with gentle mixing such as hand shaking.

The sub-micron particles contain at least one organic carrier, preferably a hydrophobic organic carrier. In addition, the composition may contain one or more of a hydrophobic organic carrier, a polar solvent, an emollient and mixtures thereof, at a concentration of about 2% to about 5%, or about 5% to about 10%, or about 10% to about 20%, or about 20% to about 50% by weight.

A “hydrophobic organic carrier” as used herein refers to a material having solubility in distilled water at ambient temperature of less than about 1 gm per 100 mL, more preferable less than about 0.5 gm per 100 mL, and most preferably less than about 0.1 gm per 100 mL. It is liquid at ambient temperature. The identification of a hydrophobic organic carrier or “hydrophobic solvent”, as used herein, is not intended to characterize the solubilization capabilities of the solvent for any specific active agent or any other component of the foamable composition. Rather, such information is provided to aid in the identification of materials suitable for use as a hydrophobic carrier in the foamable compositions described herein.

In one or more embodiments, the hydrophobic organic carrier is an oil, such as mineral oil. Mineral oil (Chemical Abstracts Service Registry number 8012-95-1) is a mixture of aliphatic, naphthalenic, and aromatic liquid hydrocarbons that derive from petroleum. It is typically liquid; its viscosity is in the range of between about 35 CST and about 100 CST (at 40° C.), and its pour point (the lowest temperature at which an oil can be handled without excessive amounts of wax crystals forming so preventing flow) is below 0° C. In one or more embodiments, the term hydrophobic organic carrier does not include thick or semi-solid materials, such as white petrolatum, also termed “Vaseline”, which, in certain compositions is disadvantageous due to its waxy nature and semi-solid texture.

According to one or more embodiments, hydrophobic solvents are liquid oils originating from vegetable, marine or animal sources. Suitable liquid oil includes saturated, unsaturated or polyunsaturated oils. By way of example, the unsaturated oil may be olive oil, corn oil, soybean oil, canola oil, cottonseed oil, coconut oil, sesame oil, sunflower oil, borage seed oil, syzigium aromaticum oil, hempseed oil, herring oil, cod-liver oil, salmon oil, flaxseed oil, wheat germ oil, evening primrose oils or mixtures thereof, in any proportion.

Suitable hydrophobic solvents also include polyunsaturated oils containing poly-unsaturated fatty acids. In one or more embodiments, said unsaturated fatty acids are selected from the group of omega-3 and omega-6 fatty acids. Examples of such polyunsaturated fatty acids are linoleic and linolenic acid, gamma-linoleic acid (GLA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Such unsaturated fatty acids are known for their skin-conditioning effect, which contribute to the therapeutic benefit of the present foamable composition. Thus, the hydrophobic solvent can include at least 6% of an oil selected from omega-3 oil, omega-6 oil, and mixtures thereof. In the context of the present invention, oils that possess therapeutically beneficial properties are termed “therapeutically active oil.”

Another class of hydrophobic solvents is the essential oils, which are also considered therapeutically active oil, which contain active biologically occurring molecules and, upon topical application, exert a therapeutic effect, which is conceivably synergistic to the beneficial effect of the NSAID in the composition.

Another class of therapeutically active oils includes liquid hydrophobic plant-derived oils, which are known to possess therapeutic benefits when applied topically.

Silicone oils also may be used and are desirable due to their known skin protective and occlusive properties. Suitable silicone oils include non-volatile silicones, such as polyalkyl siloxanes, polyaryl siloxanes, polyalkylaryl siloxanes and polyether siloxane copolymers, polydimethylsiloxanes (dimethicones) and poly(dimethylsiloxane)-(diphenyl-siloxane) copolymers. These are chosen from cyclic or linear polydimethylsiloxanes containing from about 3 to about 9, preferably from about 4 to about 5, silicon atoms. Volatile silicones such as cyclomethicones can also be used. Silicone oils are also considered therapeutically active oil, due to their barrier retaining and protective properties.

The organic carrier may be a mixture of two or more of the above hydrophobic solvents in any proportion.

A further class of organic carriers includes “emollients” that have a softening or soothing effect, especially when applied to body areas, such as the skin and mucosal surfaces. Emollients are not necessarily hydrophobic. Examples of suitable emollients include hexyleneglycol, propylene glycol, isostearic acid derivatives, isopropyl palmitate, isopropyl isostearate, diisopropyl adipate, diisopropyl dimerate, maleated soybean oil, octyl palmitate, cetyl lactate, cetyl ricinoleate, tocopheryl acetate, acetylated oil bodies alcohol, cetyl acetate, phenyl trimethicone, glyceryl oleate, tocopheryl linoleate, wheat germ glycerides, arachidyl propionate, myristyl lactate, decyl oleate, propylene glycol ricinoleate, isopropyl lanolate, pentaerythrityl tetrastearate, neopentylglycol dicaprylate/dicaprate, isononyl isononanoate, isotridecyl isononanoate, myristyl myristate, triisocetyl citrate, octyl dodecanol, sucrose esters of fatty acids, octyl hydroxystearate and mixtures thereof.

According to one or more embodiments of the present invention, the organic carrier includes a mixture of a hydrophobic solvent and an emollient. According to one or more embodiments, the foamable composition is a mixture of mineral oil and an emollient in a ratio between 2:8 and 8:2 on a weight basis.

A “polar solvent” is an organic solvent, typically soluble in both water and oil. Examples of polar solvents include polyols, such as glycerol (glycerin), propylene glycol, hexylene glycol, diethylene glycol, propylene glycol n-alkanols, terpenes, di-terpenes, tri-terpenes, terpen-ols, limonene, terpene-ol, 1-menthol, dioxolane, ethylene glycol, other glycols, sulfoxides, such as dimethylsulfoxide (DMSO), dimethylformanide, methyl dodecyl sulfoxide, dimethylacetamide, monooleate of ethoxylated glycerides (with 8 to 10 ethylene oxide units), azone (1-dodecylazacycloheptan-2-one), 2-(n-nonyl)-1,3-dioxolane, esters, such as isopropyl myristate/palmitate, ethyl acetate, butyl acetate, methyl proprionate, capric/caprylic triglycerides, octylmyristate, dodecyl-myristate; myristyl alcohol, lauryl alcohol, lauric acid, lauryl lactate ketones; amides, such as acetamide oleates such as triolein; various alkanoic acids such as caprylic acid; lactam compounds, such as azone; alkanols, such as dialkylamino acetates, and admixtures thereof.

According to one or more embodiments, the polar solvent is a polyethylene glycol (PEG) or PEG derivative that is liquid at ambient temperature, including PEG200 (MW (molecular weight) about 190-210 kD), PEG300 (MW about 285-315 kD), PEG400 (MW about 380-420 kD), PEG600 (MW about 570-630 kD) and higher MW PEGs such as PEG 4000, PEG 6000 and PEG 10000 and mixtures thereof.

According to one or more embodiments, the foamable composition is substantially alcohol-free, i.e., free of short chain alcohols. Short chain alcohols, having up to 5 carbon atoms in their carbon chain skeleton and one hydroxyl group, such as ethanol, propanol, isopropanol, butanol, iso-butanol, t-butanol and pentanol, are considered less desirable solvents or polar solvents due to their skin-irritating effect. Thus, the composition is substantially alcohol-free and includes less than about 5% final concentration of lower alcohols, preferably less than about 2%, more preferably less than about 1%.

The composition includes a stabilizing agent, which may be a polymeric agent. The polymeric agent serves to stabilize the foam composition and to control drug residence in the target organ. Exemplary polymeric agents are classified below in a non-limiting manner. In certain cases, a given polymer can belong to more than one of the classes provided below.

The polymeric agent may be a gelling agent. A gelling agent controls the residence of a therapeutic composition in the target site of treatment by increasing the viscosity of the composition, thereby limiting the rate of its clearance from the site. Many gelling agents are known in the art to possess mucoadhesive properties.

The gelling agent can be a natural gelling agent, a synthetic gelling agent and an inorganic gelling agent. Exemplary gelling agents that can be used in accordance with one or more embodiments of the present invention include, for example, microcrystalline cellulose, Aculyn a Hydrophobically-modified Ethoxylated Urethane, naturally-occurring polymeric materials, such as locust bean gum, sodium alginate, sodium caseinate, egg albumin, gelatin agar, carrageenin gum, sodium alginate, xanthan gum, quince seed extract, tragacanth gum, guar gum, starch, chemically modified starches and the like, semi-synthetic polymeric materials such as cellulose ethers (e.g. hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, hydroxy propylmethyl cellulose), guar gum, hydroxypropyl guar gum, soluble starch, cationic celluloses, cationic guars, and the like, and synthetic polymeric materials, such as carboxyvinyl polymers, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid polymers, polymethacrylic acid polymers, polyvinyl acetate polymers, polyvinyl chloride polymers, polyvinylidene chloride polymers and the like. Mixtures of the above compounds are contemplated.

Further exemplary gelling agents include the acrylic acid/ethyl acrylate copolymers and the carboxyvinyl polymers sold, for example, by the B.F. Goodrich Company under the trademark of Carbopol® resins. These resins consist essentially of a colloidal water-soluble polyalkenyl polyether crosslinked polymer of acrylic acid crosslinked with from 0.75% to 2% of a crosslinking agent such as polyallyl sucrose or polyallyl pentaerythritol. Examples include Carbopol® 934, Carbopol® 940, Carbopol® 950, Carbopol® 980, Carbopol® 951 and Carbopol® 981. Carbopol® 934 is a water-soluble polymer of acrylic acid crosslinked with about 1% of a polyallyl ether of sucrose having an average of about 5.8 allyl groups for each sucrose molecule.

The gelling agent may be a water-soluble cellulose ether. Preferably, the water-soluble cellulose ether is selected from the group consisting of methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose (Methocel), hydroxyethyl cellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, hydroxyethylcarboxymethylcellulose, carboxymethylcellulose and carboxymethylhydroxyethylcellulose. More preferably, the water-soluble cellulose ether is selected from the group consisting of methylcellulose, hydroxypropyl cellulose and hydroxypropyl methylcellulose (Methocel). In one or more embodiments, the composition includes a combination of a water-soluble cellulose ether; and a naturally-occurring polymeric materials, selected from the group including xanthan gum, guar gum, carrageenan gum, locust bean gum and tragacanth gum.

Yet, in other embodiments, the gelling agent includes inorganic gelling agents, such as silicone dioxide (fumed silica).

The polymeric agent may be a mucoadhesive agent. Mucoadhesion/bioadhesion is defined as the attachment of synthetic or biological macromolecules to a biological tissue. Mucoadhesive agents are a class of polymeric biomaterials that exhibit the basic characteristic of a hydrogel, i.e. swell by absorbing water and interacting by means of adhesion with the mucous that covers epithelia. Compositions of the present invention may contain a mucoadhesive macromolecule or polymer in an amount sufficient to confer bioadhesive properties. The bioadhesive macromolecule enhances the delivery of biologically active agents on or through the target surface. The mucoadhesive macromolecule may be selected from acidic synthetic polymers, preferably having at least one acidic group per four repeating or monomeric subunit moieties, such as poly(acrylic)- and/or poly(methacrylic) acid (e.g., Carbopol®, Carbomer®), poly(methylvinyl ether/maleic anhydride) copolymer, and their mixtures and copolymers; acidic synthetically modified natural polymers, such as carboxymethylcellulose (CMC); neutral synthetically modified natural polymers, such as (hydroxypropyl)methylcellulose; basic amine-bearing polymers such as chitosan; acidic polymers obtainable from natural sources, such as alginic acid, hyaluronic acid, pectin, gum tragacanth, and karaya gum; and neutral synthetic polymers, such as polyvinyl alcohol or their mixtures. An additional group of mucoadhesive polymers includes natural and chemically modified cyclodextrin, especially hydroxypropyl-β-cyclodextrin. Such polymers may be present as free acids, bases, or salts, usually in a final concentration of about 0.01% to about 0.5% by weight.

A suitable bioadhesive macromolecule is the family of acrylic acid polymers and copolymers, (e.g., Carbopol®). These polymers contain the general structure —[CH₂—CH(COOH)—]_(n). Hyaluronic acid and other biologically-derived polymers may be used.

Exemplary bioadhesive or mucoadhesive macromolecules have a molecular weight of at least 50 kDa, or at least 300 kDa, or at least 1,000 kDa. Favored polymeric ionizable macromolecules have not less than 2 mole percent acidic groups (e.g., COOH, SO3H) or basic groups (NH2, NRH, NR2), relative to the number of monomeric units. The acidic or basic groups can constitute at least 5 mole percent, or at least 10 mole percent, or at least 25, at least 50 mole percent, or even up to 100 mole percent relative to the number of monomeric units of the macromolecule.

Yet, another group of mucoadhesive agent includes inorganic gelling agents such as silicon dioxide (fumed silica), including but not limited to, AEROSIL 200 (DEGUSSA).

Many mucoadhesive agents are known in the art to also possess gelling properties.

The polymeric agent may be a film forming component. The film forming component may include at least one water-insoluble alkyl cellulose or hydroxyalkyl cellulose. Exemplary alkyl cellulose or hydroxyalkyl cellulose polymers include ethyl cellulose, propyl cellulose, butyl cellulose, cellulose acetate, hydroxypropyl cellulose, hydroxybutyl cellulose, and ethylhydroxyethyl cellulose, alone or in combination. In addition, a plasticizer or a cross linking agent may be used to modify the polymer's characteristics. For example, esters such as dibutyl or diethyl phthalate, amides such as diethyldiphenyl urea, vegetable oils, fatty acids and alcohols such as oleic and myristyl acid may be used in combination with the cellulose derivative.

The polymeric agent may be a phase change polymer, which alters the composition behavior from fluid-like prior to administration to solid-like upon contact with the target mucosal surface. Such phase change results from external stimuli, such as changes in temperature or pH and exposure to specific ions (e.g., Ca²⁺). Non-limiting examples of phase change polymers include poly(N-isopropylamide), Poloxamer 407® and Smart-Gel® (Poloxamer+PAA). The polymeric agent is present in an amount in the range of about 0.01% to about 5.0% by weight of the foam composition. In one or more embodiments, it is typically less than about 1 wt % of the foamable composition.

Surface-Active Agent

The stabilizing agent may also be a surface-active agent. Surface-active agents (also termed “surfactants”) include any agent linking oil and water in the composition, in the form of emulsion. A surfactant's hydrophilic/lipophilic balance (HLB) describes the emulsifier's affinity toward water or oil. HLB is defined for non-ionic surfactants. The HLB scale ranges from 1 (totally lipophilic) to 20 (totally hydrophilic), with 10 representing an equal balance of both characteristics. Lipophilic emulsifiers form water-in-oil (w/o) emulsions; hydrophilic surfactants form oil-in-water (o/w) emulsions. The HLB of a blend of two emulsifiers equals the weight fraction of emulsifier A times its HLB value plus the weight fraction of emulsifier B times its HLB value (weighted average). In many cases a single surfactant may suffice. In other cases a combination of two or more surfactants is desired. Reference to a surfactant in the specification can also apply to a combination of surfactants or a surfactant system. As will be appreciated by a person skilled in the art which surfactant or surfactant system is more appropriate is related to the vehicle and intended purpose. In general terms a combination of surfactants is usually preferable where the vehicle is an emulsion. In an emulsion environment a combination of surfactants can be significant in producing breakable forms of good quality. It has been further discovered that the generally thought considerations for HLB values for selecting a surfactant or surfactant combination are not always binding for emulsions and that good quality foams can be produced with a surfactant or surfactant combination both where the HLB values are in or towards the lipophilic side of the scale and where the HLB values are in or towards the hydrophilic side of the scale. Surfactants also play a role in foam formation where the foamable formulation is a single phase composition.

The relationship between oil and surfactant is indicated by the required predicted HLB for the oil and the parallel theoretical HLB of the surfactant as shown in the non limiting examples below.

HLB RHLB White Petrolatum (sofmetic) 7.0 Isopropyl myristate 11.5 Octyl dodecanol light Mineral oil 10.5 Diisopropyl adipate 9.0 PPG 15 Stearyl ether 7.0 Cetearyl alcohol 15.5 Steareth-2 4.9 Steareth 21 15.5 Glyceryl monostearate 3.8 PEG-40 stearate 16.9 Polyoxyl 100 monostearate 18.8 Stearyl alcohol 15.5 Polysorbate 80 15.0

According to one or more embodiments the composition contains a single surfactant having an HLB value between about 2 and 9, or more than one surfactant and the weighted average of their HLB values is between about 2 and about 9. Lower HLB values may in certain embodiments be more applicable to water in oil emulsions.

According to one or more embodiments the composition contains a single surfactant having an HLB value between about 7 and 14, or more than one surfactant and the weighted average of their HLB values is between about 7 and about 14. Mid range HLB values may in certain embodiments be more suitable for oil in water nano emulsion s.

According to one or more other embodiments the composition contains a single surfactant having an HLB value between about 9 and about 19, or more than one surfactant and the weighted average of their HLB values is between about 9 and about 19. In a waterless or substantially waterless environment a wide range of HLB values may be suitable.

Preferably, the composition of the present invention contains a non-ionic surfactant. Nonlimiting examples of possible non-ionic surfactants include a polysorbate, polyoxyethylene (20) sorbitan monostearate, polyoxyethylene (20) sorbitan monooleate, a polyoxyethylene fatty acid ester, Myrj 45, Myrj 49, Myrj 52 and Myrj 59; a polyoxyethylene alkyl ether, polyoxyethylene cetyl ether, polyoxyethylene palmityl ether, polyethylene oxide hexadecyl ether, polyethylene glycol cetyl ether, steareths such as steareth 2, brij 21, brij 721, brij 38, brij 52, brij 56 and brij W1, a sucrose ester, a partial ester of sorbitol and its anhydrides, sorbitan monolaurate, sorbitan monolaurate, a monoglyceride, a diglyceride, isoceteth-20 and mono-, di- and tri-esters of sucrose with fatty acids. In certain embodiments, suitable sucrose esters include those having high monoester content, which have higher HLB values.

In certain embodiments with wax as emollient, surfactants are selected which can provide a close packed surfactant layer separating the oil and water phases. To achieve such objectives combinations of at least two surfactants are selected. Preferably, they should be complex emulgators and more preferably they should both be of a similar molecular type. For example, a pair of ethers like steareth 2 and steareth 21, or a pair of esters for example, PEG-40 stearate and polysorbate 80. In certain circumstances POE esters cannot be used and a combination of sorbitan laurate and sorbitan stearate or a combination of sucrose stearic acid ester mixtures and sodium laurate may be used. All these combinations due to their versatility and strength may also be used satisfactorily and effectively with wax formulations, although the amounts and proportion may be varied according to the formulation and its objectives as will be appreciated by a man of the art.

It has been discovered also that by using a derivatized hydrophilic polymer with hydrophobic alkyl moieties as a polymeric emulsifier such as pemulen it is possible to stabilize the emulsion better about or at the region of phase reversal tension. Other types of derivatized polymers like silicone copolymers, derivatized starch [Aluminum Starch Octenylsuccinate (ASOS)]/[DRY-FLO AF Starch], and derivatized dexrin may also a similar stabilizing effect.

A series of dextrin derivative surfactants prepared by the reaction of the propylene glycol polyglucosides with a hydrophobic oxirane-containing material of the glycidyl ether are highly biodegradable. [Hong-Rong Wang and Keng-Ming Chen, Colloids and Surfaces A: Physicochemical and Engineering Aspects Volume 281, Issues 1-3, 15 Jun. 2006, Pages 190-193].

Non-limiting examples of non-ionic surfactants that have HLB of about 7 to about 12 include steareth 2 (HLB˜4.9); glyceryl monostearate/PEG 100 stearate (Av HLB˜11.2); stearate Laureth 4 (HLB˜9.7) and cetomacrogol ether (e.g., polyethylene glycol 1000 monocetyl ether).

Non-limiting examples of preferred surfactants, which have a HLB of 4-19 are set out in the Table below:

Surfactant HLB steareth 2 ~4.9 glyceryl monostearate/PEG 100 stearate Av ~11.2 Glyceryl Stearate ~4 Steareth-21 ~15.5 peg 40 stearate ~16.9 polysorbate 80 ~15 sorbitan stearate ~4.7 laureth 4 ~9.7 Sorbitan monooleate (span 80) ~4.3 ceteareth 20 ~15.7 steareth 20 ~15.3 Ceteth 20 ~15.7 Macrogol Cetostearyl Ether ~15.7 Ceteth 2 (Lipocol C-2) ~5.3 PEG-30 Dipolyhydroxystearate ~5.5 sucrose distearate (Sisterna SP30) ~6 polyoxyethylene (100) stearate ~18.8

In one or more embodiments the surfactant is a complex emulgator in which the combination of two or more surfactants can be more effective than a single surfactant and provides a more stable emulsion or improved foam quality than a single surfactant. For example and by way of non-limiting explanation it has been found that by choosing say two surfactants, one hydrophobic and the other hydrophilic the combination can produce a more stable emulsion than a single surfactant. Preferably, the complex emulgator comprises a combination of surfactants wherein there is a difference of about 4 or more units between the HLB values of the two surfactants or there is a significant difference in the chemical nature or structure of the two or more surfactants.

Specific non limiting examples of surfactant systems are, combinations of polyoxyethylene alkyl ethers, such as Brij 59/Brij10; Brij 52/Brij 10; Steareth 2/Steareth 20; Steareth 2/Steareth 21 (Brij 72/Brij 721); combinations of polyoxyethylene stearates such as Myrj 52/Myrj 59; combinations of sucrose esters, such as Surphope 1816/Surphope 1807; combinations of sorbitan esters, such as Span 20/Span 80; Span 20/Span 60; combinations of sucrose esters and sorbitan esters, such as Surphope 1811 and Span 60; combinations of liquid polysorbate detergents and PEG compounds, such as Tween 80/PEG-40 stearate; methyl glucaso sequistearate; polymeric emulsifiers, such as Permulen (TRI or TR2); liquid crystal systems, such as Arlatone (2121), Stepan (Mild RM1), Nikomulese (41) and Montanov (68) and the like.

In certain embodiments the surfactant is preferably one or more of the following: a combination of steareth-2 and steareth-21 on their own or in combination with glyceryl monostearate (GMS); in certain other embodiments the surfactant is a combination of polysorbate 80 and PEG-40 stearate. In certain other embodiments the surfactant is a combination of glyceryl monostearate/PEG 100 stearate. In certain other embodiments the surfactant is a combination of two or more of stearate 21, PEG 40 stearate, and polysorbate 80. In certain other embodiments the surfactant is a combination of two or more of laureth 4, span80, and polysorbate 80. In certain other embodiments the surfactant is a combination of two or more of GMS and ceteareth. In certain other embodiments the surfactant is a combination of two or more of steareth 21, ceteareth 20, ceteth 2 and laureth 4 In certain other embodiments the surfactant is a combination of ceteareth 20 and polysorbate 40 stearate. In certain other embodiments the surfactant is a combination of span 60 and GMS. In certain other embodiments the surfactant is a combination of two or all of PEG 40 stearate, sorbitan stearate and polysorbate 60

In certain other embodiments the surfactant is one or more of sucrose stearic acid esters, sorbitan laureth, and sorbitan stearate.

Without being bound by any particular theory or mode of operation, it is believed that the use of non-ionic surfactants with significant hydrophobic and hydrophilic components, increase the emulsifier or foam stabilization characteristics of the composition. Similarly, without being bound by any particular theory or mode of operation, using combinations of surfactants with high and low HLB's to provide a relatively close packed surfactant layer may strengthen the emulsion.

In one or more embodiments the stability of the composition can be improved when a combination of at least one non-ionic surfactant having HLB of less than 9 and at least one non-ionic surfactant having HLB of equal or more than 9 is employed. The ratio between the at least one non-ionic surfactant having HLB of less than 9 and the at least one non-ionic surfactant having HLB of equal or more than 9, is between 1:8 and 8:1, or at a ratio of 4:1 to 1:4. The resultant HLB of such a blend of at least two emulsifiers is preferably between about 9 and about 14.

Thus, in an exemplary embodiment, a combination of at least one non-ionic surfactant having HLB of less than 9 and at least one non-ionic surfactant having HLB of equal or more than 9 is employed, at a ratio of between 1:8 and 8:1, or at a ratio of 4:1 to 1:4, wherein the HLB of the combination of emulsifiers is preferably between about 5 and about 18.

In certain cases, the surfactant is selected from the group of cationic, zwitterionic, amphoteric and ampholytic surfactants, such as sodium methyl cocoyl taurate, sodium methyl oleoyl taurate, sodium lauryl sulfate, triethanolamine lauryl sulfate and betaines.

Many amphiphilic molecules can show lyotropic liquid-crystalline phase sequences depending on the volume balances between the hydrophilic part and hydrophobic part. These structures are formed through the micro-phase segregation of the two parts. Many amphiphilic molecules can show lyotropic liquid-crystalline phase sequences depending on the volume balances between the hydrophilic part and hydrophobic part. These structures are formed through the micro-phase segregation of two incompatible components on a nanometer scale. Soap is an everyday example of a lyotropic liquid crystal. Certain types of surfactants tend to form lyotropic liquid crystals in emulsions interface (oil-in-water) and exert a stabilizing effect

In one or more embodiments the surfactant is a surfactant or surfactant combination is capable of or which tends to form liquid crystals. Surfactants which tend to form liquid crystals may improve the quality of foams. Non limiting examples of surfactants with postulated tendency to form interfacial liquid crystals are: phospholipids, alkyl glucosides, sucrose esters, sorbitan esters.

In one or more embodiments the at least one surfactant is liquid.

In one or more embodiments the liquid surfactant is a polysorbate, preferably polysorbate 80 or 60.

In one or more embodiments the at least one surfactant is solid, semi solid or waxy.

It should be noted that HLB values may not be so applicable to non ionic surfactants, for example, with liquid crystals or with silicones. Also HLB values may be of lesser significance in a waterless or substantially non-aqueous environment.

In one or more embodiments the surfactant can be, a surfactant system comprising of a surfactant and a co surfactant, a waxy emulsifier, a liquid crystal emulsifier, an emulsifier which is solid or semi solid at room temperature and pressure, or combinations of two or more agents in an appropriate proportion as will be appreciated a person skilled in the art. Where a solid or semi solid emulsifier combination is used it can also comprise a solid or semi solid emulsifier and a liquid emulsifier.

In one or more embodiments of the present invention, the surface-active agent includes at least one non-ionic surfactant. Ionic surfactants are known to be irritants. Therefore, non-ionic surfactants are preferred in applications including sensitive tissue such as found in most mucosal tissues, especially when they are infected or inflamed. Non-ionic surfactants alone can provide formulations and foams of good or excellent quality in the carriers and compositions of the present invention.

Thus, in a preferred embodiment, the surfactant, the composition contains a non-ionic surfactant. In another preferred embodiment the composition includes a mixture of non-ionic surfactants as the sole surfactant. Yet, in additional embodiments, the foamable composition includes a mixture of at least one non-ionic surfactant and at least one ionic surfactant in a ratio in the range of about 100:1 to 6:1. In one or more embodiments, the non-ionic to ionic surfactant ratio is greater than about 6:1, or greater than about 8:1; or greater than about 14:1, or greater than about 16:1, or greater than about 20:1. In further embodiments, surfactant comprises a combination of a non-ionic surfactant and an ionic surfactant, at a ratio of between 1:1 and 20:1

In one or more embodiments of the present invention, a combination of a non-ionic surfactant and an ionic surfactant (such as sodium lauryl sulphate and cocamidopropylbetaine) is employed, at a ratio of between 1:1 and 20:1, or at a ratio of 4:1 to 10:1; for example, about 1:1, about 4:1, about 8:1, about 12:1, about 16:1 and about 20:1 or at a ratio of 4:1 to 10:1, for example, about 4:1, about 6:1, about 8:1 and about 10:1.

In selecting a suitable surfactant or combination thereof it should be borne in mind that the upper amount of surfactant that may be used may be limited by the shakability of the composition. If the surfactant is non liquid, it can make the formulation to viscous or solid. This can be particularly significant if the formulation has high molecular weight, e.g., a high molecular weight PEG or polymeric agents or petroleum or if the surfactants are large. Solvents and polymeric agents which have high molecular weight and are very viscous or solid or waxy (e.g., Peg 1500, 2000, etc. or petrolatum) can exacerbate the effect of a waxy or solid surfactant on shakability or flowability In general terms, as the amount of non-liquid surfactant is increased the shakability of the formulation reduces until a limitation point is reached where the formulation becomes non shakable and unsuitable. Thus in one embodiment, an effective amount of surfactant may be used provided the formulation remains shakable. In other certain exceptional embodiments the upper limit may be determined by flowability such as in circumstances where the composition is marginally or apparently non-shakable. The formulation is sufficiently flowable to be able to flow through an actuator valve and be released and still expand to form a good quality foam.

In certain embodiments of the present invention the amount of surfactant or combination of surfactants is between about 0.05% to about 20%; between about 0.05% to about 15%. or between about 0.05% to about 10%. In a preferred embodiment the concentration of surfactant is between about 0.2% and about 8%. In a more preferred embodiment the concentration of surfactant is between about 1% and about 6%. In one or more preferred embodiments the surfactant oil ratio is relatively high ranging from about of the order of 1:1 to about 1:10. Nevertheless lower levels are possible.

In some embodiments, it is desirable that the surfactant does not contain a polyoxyethylene (POE) moiety, such as polysorbate surfactants, POE fatty acid esters, and POE alkyl ethers, because the active agent is incompatible with such surfactants. For example, the active agent pimecrolimus is not stable the presence of POE moieties, yet benefits greatly from the use of dicarboxylic esters as penetration enhancers. In such cases, alternative surfactants are employed. In an exemplary manner, POE—free surfactants include non-ethoxylated sorbitan esters, such as sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, sorbitan monolaurate and sorbitan sesquioleate; glycerol fatty acid esters, such as glycerol monostearate and glycerol monooleate; mono-, di- and tri-esters of sucrose with fatty acids (sucrose esters), sucrose stearate, sucrose distearate sucrose palmitate and sucrose laurate; and alkyl polyglycosides, such as lauryl diglucoside.

If the composition as formulated is a substantially non shakable composition it is nevertheless possible as an exception in the scope of the present invention for the formulation to be flowable to a sufficient degree to be able to flow through an actuator valve and be released and still expand to form a good quality foam. This surprising and unusual exception may be due one or more of a number of factors such as the high viscosity, the softness, the lack of crystals, the pseudoplastic or semi pseudo plastic nature of the composition and the dissolution of the propellant into the composition. The propellant can change a merely flowable composition into a shakable one.

In one or more embodiments of the present invention, the surface-active agent includes mono-, di- and tri-esters of sucrose with fatty acids (sucrose esters), prepared from sucrose and esters of fatty acids or by extraction from sucro-glycerides. Suitable sucrose esters include those having high monoester content, which have higher HLB values.

The surface-active agent is selected from anionic, cationic, nonionic, zwitterionic, amphoteric and ampholytic surfactants, as well as mixtures of these surfactants.

In the case wherein the oil globules are oil bodies, the surfactant can be the phospholipids or the oil bodies.

Combination of surfactants are contemplated. In regular emulsion compositions the total surfactant is usually in the range of about 0.1 to about 5% of the foamable composition, and is typically less than about 2% or less than about 1%. However in order to form nano emulsions it may be appropriate to use higher levels of surfactant, particularly if nanoemulsions are desired with a diameter size in the range of about less than 500 nanometers. Thus, the total surfactant may be in the range of about 5% to about 25% and may preferably be in the range of about 6% to about 12%. In another preferred embodiment the total is about 8%.

In one or more embodiments the surfactant plays a role in the determination of the viscosity of the formulation. In particular without being bound by any theory the surfactants may have an inherent role in the surprising loss or reduction of viscosity to less than 500 cP even though the viscosity of the formulation can be much higher prior to nano processing with say up to six cycles with a high pressure homogenizer.

Substantially Alcohol-Free

According to one or more embodiments, the foamable composition is substantially alcohol-free, i.e., free of short chain alcohols. Short chain alcohols, having up to 5 carbon atoms in their carbon chain skeleton and one hydroxyl group, such as ethanol, propanol, isopropanol, butaneol, iso-butaneol, t-butaneol and pentanol, are considered less desirable solvents or polar solvents due to their skin-irritating effect. Thus, the composition is substantially alcohol-free and includes less than about 5% final concentration of lower alcohols, preferably less than about 2%, more preferably less than about 1%.

Shakability

‘Shakability’ means that the composition contains some or sufficient flow to allow the composition to be mixed or remixed on shaking. That is, it has fluid or semi fluid properties. In some very limited cases possibly aided by the presence of silicone it may exceptionally be possible to have a foamable composition which is flowable but not apparently shakable.

Breakability

A breakable foam is one that is thermally stable, yet breaks under sheer force.

The breakable foam of the present invention is not “quick breaking”, i.e., it does not readily collapse upon exposure to body temperature environment. Sheer-force breakability of the foam is clearly advantageous over thermally induced breakability, since it allows comfortable application and well directed administration to the target area.

Preferably, foam adjuvant is included in the foamable compositions of the present invention to increase the foaming capacity of surfactants and/or to stabilize the foam. In one or more embodiments of the present invention, the foam adjuvant agent includes fatty alcohols having 15 or more carbons in their carbon chain, such as cetyl alcohol and stearyl alcohol (or mixtures thereof). Other examples of fatty alcohols are arachidyl alcohol (C20), behenyl alcohol (C22), 1-triacontanol (C30), as well as alcohols with longer carbon chains (up to C50). Fatty alcohols, derived from beeswax and including a mixture of alcohols, a majority of which has at least 20 carbon atoms in their carbon chain, are especially well suited as foam adjuvant agents. The amount of the fatty alcohol required to support the foam system is inversely related to the length of its carbon chains. Foam adjuvants, as defined herein are also useful in facilitating improved spreadability and absorption of the composition.

In one or more embodiments of the present invention, the foam adjuvant agent includes fatty acids having 16 or more carbons in their carbon chain, such as hexadecanoic acid (C16) stearic acid (C18), arachidic acid (C20), behenic acid (C22), octacosanoic acid (C28), as well as fatty acids with longer carbon chains (up to C50), or mixtures thereof. As for fatty alcohols, the amount of fatty acids required to support the foam system is inversely related to the length of its carbon chain.

Optionally, the carbon atom chain of the fatty alcohol or the fatty acid may have at least one double bond. A further class of foam adjuvant agent includes a branched fatty alcohol or fatty acid. The carbon chain of the fatty acid or fatty alcohol also can be substituted with a hydroxyl group, such as 12-hydroxy stearic acid.

An important property of the fatty alcohols and fatty acids used in context of the composition of the present invention is related to their therapeutic properties per se. Long chain saturated and mono unsaturated fatty alcohols, e.g., stearyl alcohol, erucyl alcohol, arachidyl alcohol and behenyl alcohol (docosanol) have been reported to possess antiviral, antiinfective, antiproliferative and antiinflammatory properties (see, for example, U.S. Pat. No. 4,874,794). Longer chain fatty alcohols, e.g., tetracosanol, hexacosanol, heptacosanol, octacosanol, triacontanol, etc., are also known for their metabolism modifying properties and tissue energizing properties. Long chain fatty acids have also been reported to possess anti-infective characteristics.

Thus, in preferred embodiments of the present invention, a combined and enhanced therapeutic effect is attained by including both a nonsteroidal immunomodulating agent and a therapeutically effective foam adjuvant in the same composition, thus providing a simultaneous anti-inflammatory and antiinfective effect from both components. Furthermore, in a further preferred embodiment, the composition concurrently comprises a nonsteroidal immunomodulating agent, a therapeutically effective foam adjuvant and a therapeutically active oil, as detailed above. Such combination provides an even more enhanced therapeutic benefit. Thus, the foamable carrier, containing the foam adjuvant provides an extra therapeutic benefit in comparison with currently used vehicles, which are inert and non-active.

The foam adjuvant according to preferred embodiments of the present invention includes a mixture of fatty alcohols, fatty acids and hydroxy fatty acids and derivatives thereof in any proportion, providing that the total amount is 0.1% to 5% (w/w) of the carrier mass. More preferably, the total amount is 0.4%-2.5% (w/w) of the carrier mass.

The foam of the present invention may further optionally include a variety of formulation excipients, which are added in order to fine-tune the consistency of the formulation, protect the formulation components from degradation and oxidation and modify their consistency. Such excipients may be selected, for example, from stabilizing agents, antioxidants, humectants, preservatives, colorant and odorant agents and other formulation components, used in the art of formulation.

Propellants

Aerosol propellants are used to generate and administer the foamable composition as a foam. Suitable propellants include volatile hydrocarbons such as butane, propane, isobutane and fluorocarbon gases, or mixtures thereof.

In an embodiment of the present invention the propellant is AP 70 which is a mixture of propane, isobutene and butane. In another embodiment the propellant is AP 46 which is a similar mixture of propane, isobutene and butane but having a lower pressure. AP 70 offers about 50% higher pressure than AP 46.

The propellant makes up about 3-25 wt % of the foamable composition. In some circumstances the propellant may be up to 35%. The propellants are used to generate and administer the foamable composition as a foam. The total composition including propellant, foamable compositions and optional ingredients can be referred to as the foamable composition.

Alcohol and organic solvents render foams inflammable. It has been surprisingly discovered that fluorohydrocarbon propellants, other than chloro-fluoro carbons (CMOs), which are non-ozone-depleting propellants, are particularly useful in the production of a non-flammable foamable composition. A test according to European Standard prEN 14851, titled “Aerosol containers—Aerosol foam flammability test” revealed that compositions containing an organic carrier that contains a hydrophobic organic carrier and/or a polar solvent, which are detected as inflammable when a hydrocarbon propellant is used, become non-flammable, while the propellant is an HFC propellant.

Such propellants include, but are not limited to, hydrofluorocarbon (HFC) propellants, which contain no chlorine atoms, and as such, fall completely outside concerns about stratospheric ozone destruction by chlorofluorocarbons or other chlorinated hydrocarbons. Exemplary non-flammable propellants according to this aspect include propellants made by DuPont under the registered trademark Dymel, such as 1,1,1,2 tetrafluorethane (Dymel 134), and 1,1,1,2,3,3,3 heptafluoropropane (Dymel 227). HFCs possess Ozone Depletion Potential of 0.00 and thus, they are allowed for use as propellant in aerosol products.

Notably, the stability of foamable emulsions including HFC as the propellant can be improved in comparison with the same composition made with a hydrocarbon propellant.

In one or more embodiments foamable compositions comprise a combination of a HFC and a hydrocarbon propellant such as n-butane or mixtures of hydrocarbom propellants such as propane, isobutane and butane.

Aging

In order to project the potential shelf life and stability of the compositions and their ingredients particularly active or benefit agents the compositions can subjected to a number of tests, including centrifugation to look for resistance to creaming, phase separation; one or more freeze thaw cycles, standing at room and higher temperatures as an indicator of resistance to aging.

Cosmetically or Pharmaceutically Active Agents

In one or more embodiments, the foamable composition of the present invention is a carrier of a cosmetically or pharmaceutically active agent(s). The agents may be introduced into an aqueous phase (i.e., water), or a hydrophobic phase (e.g., hydrophobic solvent or oil globules). Exemplary, non binding and cosmetically or pharmaceutically active agents include, but are not limited to an anti-infective, an antibiotic, an antibacterial agent, an antifungal agent, an antiviral agent, an antiparasitic agent, an steroidal antiinflammatory agent, an immunosuppressive agent, an immunomodulator, an immunoregulating agent, a hormonal agent, vitamin A, a vitamin A derivative, vitamin B, a vitamin B derivative, vitamin C, a vitamin C derivative, vitamin D, a vitamin D derivative, vitamin E, a vitamin E derivative, vitamin F, a vitamin F derivative, vitamin K, a vitamin K derivative, a wound healing agent, a disinfectant, an anesthetic, an antiallergic agent, an alpha hydroxyl acid, lactic acid, glycolic acid, a beta-hydroxy acid, a protein, a peptide, a neuropeptide, a allergen, an immunogenic substance, a haptene, an oxidizing agent, an antioxidant, a dicarboxylic acid, azelaic acid, sebacic acid, adipic acid, fumaric acid, a retinoid, an antiproliferative agent, an anticancer agent, a photodynamic therapy agent, an anti-wrinkle agent, a radical scavenger, a metal oxide (e.g., titanium dioxide, zinc oxide, zirconium oxide, iron oxide), silicone oxide, an anti wrinkle agent, a skin whitening agent, a skin protective agent, a masking agent, an anti-wart agent, a refatting agent, a lubricating agent and mixtures thereof. Yet, in certain embodiments, one or more components of the oil bodies or sub-micron globules act possess a therapeutic property, such as detailed hereinabove, and thus, in such embodiments, the oil bodies or sub-micron globules can be considered herein as active agents.

Composition and Foam Physical Characteristics

A pharmaceutical or cosmetic composition manufactured using the foam carrier according to one or more embodiments of the present invention is very easy to use. When applied onto the afflicted body surface of mammals, i.e., humans or animals, it is in a foam state, allowing free application without spillage. Upon further application of a mechanical force, e.g., by rubbing the composition onto the body surface, it freely spreads on the surface and is rapidly absorbed.

The foam composition of the present invention creates a stable formulation having an acceptable shelf-life of at least one year, or at least two years at ambient temperature. A feature of a product for cosmetic or medical use is long term stability. Propellants, which are a mixture of low molecular weight hydrocarbons, tend to impair the stability of emulsions. It has been observed, however, that foam compositions according to the present invention are surprisingly stable. Following accelerated stability studies, they demonstrate desirable texture; they form fine bubble structures that do not break immediately upon contact with a surface, spread easily on the treated area and absorb quickly.

The composition should also be free flowing, to allow it to flow through the aperture of the container, e.g., and aerosol container, and create an acceptable foam.

Foam quality can be graded as follows:

Grade E (excellent): very rich and creamy in appearance, does not show any bubble structure or shows a very fine (small) bubble structure; does not rapidly become dull; upon spreading on the skin, the foam retains the creaminess property and does not appear watery;

Grade G (good): rich and creamy in appearance, very small bubble size, “dulls” more rapidly than an excellent foam, retains creaminess upon spreading on the skin, and does not become watery;

Grade FG (fairly good): a moderate amount of creaminess noticeable, bubble structure is noticeable; upon spreading on the skin the product dulls rapidly and becomes somewhat lower in apparent viscosity;

Grade F (fair): very little creaminess noticeable, larger bubble structure than a “fairly good” foam, upon spreading on the skin it becomes thin in appearance and watery;

Grade P (poor): no creaminess noticeable, large bubble structure, and when spread on the skin it becomes very thin and watery in appearance; and

Grade VP (very poor): dry foam, large very dull bubbles, difficult to spread on the skin.

Topically administratable foams are typically of quality grade E or G, when released from the aerosol container. Smaller bubbles are indicative of more stable foam, which does not collapse spontaneously immediately upon discharge from the container. The finer foam structure looks and feels smoother, thus increasing its usability and appeal.

A further aspect of the foam is breakability. The foam of the present invention is thermally stable, yet breaks under sheer force. Sheer-force breakability of the foam is clearly advantageous over thermally-induced breakability. Thermally sensitive foams immediately collapse upon exposure to skin temperature and, therefore, cannot be applied on the hand and afterwards delivered to the afflicted area.

Another property of the foam is density (specific gravity), as measured upon release from the aerosol can. Typically, foams have specific gravity of (1) less than 0.12 g/mL; or (2) the range between 0.02 and 0.12; or (3) the range between 0.04 and 0.10; or (4) the range between 0.06 and 0.10.

Fields of Pharmaceutical Applications

By including oil bodies or sub-micron globules and optionally, additional active agents in the compositions of the present invention, the composition are useful in treating an animal or a human patient having any one of a variety of dermatological disorders that include dry and/or scaly skin as one or their etiological factors (also termed “dermatoses”), such as classified in a non-limiting exemplary manner according to the following groups:

Dermatitis including contact dermatitis, atopic dermatitis, seborrheic dermatitis, nummular dermatitis, chronic dermatitis of the hands and feet, generalized exfoliative dermatitis, stasis dermatitis; lichen simplex chronicus; diaper rash;

Bacterial infections including cellulitis, acute lymphangitis, lymphadenitis, erysipelas, cutaneous abscesses, necrotizing subcutaneous infections, staphylococcal scalded skin syndrome, folliculitis, furuncles, hidradenitis suppurativa, carbuncles, paronychial infections, erythrasma;

Fungal Infections including dermatophyte infections, yeast Infections; parasitic Infections including scabies, pediculosis, creeping eruption;

Viral Infections;

Disorders of hair follicles and sebaceous glands including acne, rosacea, perioral dermatitis, hypertrichosis (hirsutism), alopecia, including male pattern baldness, alopecia areata, alopecia universalis and alopecia totalis; pseudofolliculitis barbae, keratinous cyst;

Scaling papular diseases including psoriasis, pityriasis rosea, lichen planus, pityriasis rubra pilaris;

Benign tumors including moles, dysplastic nevi, skin tags, lipomas, angiomas, pyogenic granuloma, seborrheic keratoses, dermatofibroma, keratoacanthoma, keloid;

Malignant tumors including basal cell carcinoma, squamous cell carcinoma, malignant melanoma, paget's disease of the nipples, kaposi's sarcoma;

Reactions to sunlight including sunburn, chronic effects of sunlight, photosensitivity;

Bullous diseases including pemphigus, bullous pemphigoid, dermatitis herpetiformis, linear immunoglobulin A disease;

Pigmentation disorders including hypopigmentation such as vitiligo, albinism and postinflammatory hypopigmentation and hyperpigmentation such as melasma (chloasma), drug-induced hyperpigmentation, postinflammatory hyperpigmentation;

Disorders of cornification including ichthyosis, keratosis pilaris, calluses and corns, actinic keratosis;

Pressure sores;

Disorders of sweating; and

Inflammatory reactions including drug eruptions, toxic epidermal necrolysis; erythema multiforme, erythema nodosum, granuloma annulare.

According to one or more embodiments of the present invention, the compositions are also useful in the therapy of non-dermatological disorders by providing transdermal delivery of an active nonsteroidal immunomodulating agent that is effective against non-dermatological disorders.

The same advantage is expected when the composition is topically applied to a body cavity or mucosal surface (e.g., the mucosa of the nose, mouth, eye, ear, vagina or rectum) to treat conditions such as chlamydia infection, gonorrhea infection, hepatitis B, herpes, HIV/AIDS, human papillomavirus (HPV), genital warts, bacterial vaginosis, candidiasis, chancroid, granuloma Inguinale, lymphogranloma venereum, mucopurulent cervicitis (MPC), molluscum contagiosum, nongonococcal urethritis (NGU), trichomoniasis, vulvar disorders, vulvodynia, vulvar pain, yeast infection, vulvar dystrophy, vulvar intraepithelial neoplasia (VIN), contact dermatitis, pelvic inflammation, endometritis, salpingitis, oophoritis, genital cancer, cancer of the cervix, cancer of the vulva, cancer of the vagina, vaginal dryness, dyspareunia, anal and rectal disease, anal abscess/fistula, anal cancer, anal fissure, anal warts, Crohn's disease, hemorrhoids, anal itch, pruritus ani, fecal incontinence, constipation, polyps of the colon and rectum.

Other foamable compositions are described in: U.S. Publication No. 05-0232869, published on Oct. 20, 2005, entitled NONSTEROIDAL IMMUNOMODULATING KIT AND COMPOSITION AND USES THEREOF; U.S. Publication No. 05-0205086, published on Sep. 22, 2005, entitled RETINOID IMMUNOMODULATING KIT AND COMPOSITION AND USES THEREOF; U.S. Publication No. 06-0018937, published on Jan. 26, 2006, entitled STEROID KIT AND FOAMABLE COMPOSITION AND USES THEREOF; U.S. Publication No. 05-0271596, published on Dec. 8, 2005, entitled VASOACTIVE KIT AND COMPOSITION AND USES THEREOF; U.S. Publication No. 06-0269485, published on Nov. 30, 2006, entitled ANTIBIOTIC KIT AND COMPOSITION AND USES THEREOF; U.S. Publication No. 07-0020304, published on Jan. 25, 2007, entitled NON-FLAMMABLE INSECTICIDE COMPOSITION AND USES THEREOF; U.S. Publication No. 06-0193789, published on Aug. 31, 2006, entitled FILM FORMING FOAMABLE COMPOSITION; U.S. patent application Ser. No. 11/732,547, filed on Apr. 4, 2007, entitled ANTI-INFECTION AUGMENTATION OF FOAMABLE COMPOSITIONS AND KIT AND USES THEREOF; U.S. Provisional Patent Application No. 60/789,186, filed on Apr. 4, 2006, KERATOLYTIC ANTIFUNGAL FOAM; U.S. Provisional Patent Application No. 60/815,948, filed on Jun. 23, 2006, entitled FOAMABLE COMPOSITIONS COMPRISING A CALCIUM CHANNEL BLOCKER, A CHOLINERGIC AGENT AND A NITRIC OXIDE DONOR; U.S. Provisional Patent Application No. 60/818,634, filed on Jul. 5, 2006, entitled DICARBOXYLIC ACID FOAMABLE VEHICLE AND PHARMACEUTICAL COMPOSITIONS THEREOF; U.S. Provisional Patent Application No. 60/843,140, filed on Sep. 8, 2006, entitled FOAMABLE VEHICLE AND VITAMIN PHARMACEUTICAL COMPOSITIONS THEREOF, all of which are incorporated herein by reference in their entirety with reference to any of the active ingredients; penetration enhancers; humectants; moisturizers; listed therein can be applied herein and are incorporated by reference.

The following examples further exemplify the benefit agent foamable pharmaceutical carriers, pharmaceutical compositions thereof, methods for preparing the same, and therapeutic uses of the compositions. The examples are for the purposes of illustration only and are not intended to be limiting. Many variations may be carried out by one of ordinary skill in the art and are contemplated within the full scope of the present invention.

Methodology

A general procedure for preparing foamable compositions is set out in WO 2004/037225, which is incorporated herein by reference.

General PFF Preparation Nano Foams

Nano Emulsion Foam Stabilized with Hydrocolloids polymers

-   -   1. Mix oily phase ingredients and heat to 75° C. to melt all         ingredients and obtain homogeneous mixture.     -   2. Mix polymers in water with heating or cooling as appropriate         for specific polymer.     -   3. Add all other water soluble ingredients to water-polymer         solution and heat to 75° C.     -   4. Add slowly external phase to internal phase at 75° C. under         vigorous mixing and homogenize to obtain fine emulsion.     -   5. Cool to below 40° C. and add sensitive ingredients with mild         mixing.     -   6. The fine emulsion oily droplets are further finely dispersed         using high pressure homogenizer (Model M-110Y Microfluidezer®         processor, Microfluidics Corp, USA) at 1000-1500 bars pressure,         4 to 8 cycles. The temperature is kept above 40° C. during         homogenization process until viscosity drops.         Nano Emulsion Foam Stabilized with Acrylates Polymers     -   1. Mix oily phase ingredients and heat to 60° C. to melt all         ingredients and obtain homogeneous mixture.     -   2. Disperse the Acrylate polymer in the oily phase.     -   3. Mix all water soluble ingredients to water solution and heat         to 60° C.     -   4. Add slowly external phase to internal phase at 60° C. under         vigorous mixing and homogenize to obtain fine emulsion.     -   5. Cool to below 40° C. and add sensitive ingredients with mild         mixing.     -   6. The fine emulsion oily droplets are further finely dispersed         using high pressure homogenizer (Model M-110Y Microfluidezer®         processor, Microfluidics Corp, USA) at 1000-1500 bars pressure,         4 to 8 cycles. The temperature is kept above 40° C. during         homogenization process until viscosity drops.

Emulsion Foam

-   -   1. Mix oily phase ingredients and heat to 75° C. to melt all         ingredients and obtain homogeneous mixture.     -   2. Mix polymers in water with heating or cooling as appropriate         for specific polymer. Whilst the polymers may be added instead         into the oily phase it was found to be advantageous to prepare         them in the water phase.     -   3. Add all other water soluble ingredients to water-polymer         solution and heat to 75° C.     -   4. Add slowly internal phase to external phase at 75° C. under         vigorous mixing and homogenize to obtain fine emulsion.         Alternatively the external phase is added slowly to the internal         phase.     -   5. Cool to below 40° C. and add sensitive ingredients with mild         mixing.     -   6. Cool to room temperature.

Waterless Foam

-   -   1. Dissolve the polymers in the main solvent with heating or         cooling as appropriate for specific polymer. Add the all other         ingredients and heat to 75° C. to melt and dissolve the various         ingredients.     -   2. Cool to below 40° C. and add sensitive ingredients with mild         mixing.     -   3. Cool to room temperature.

Oily Waterless Foam

-   -   1. Mix all ingredients excluding polymers and heat to 75° C. to         melt and dissolve and obtain homogeneous mixture.     -   2. Mix well and cool to below 40° C. and add the polymers and         sensitive ingredients with moderate mixing.     -   3. Cool to room temperature.         Oily Foam with Phospholipids and/or Water     -   1. Swell the phospholipids in the main oily solvent under mixing         for at least 20 minutes until uniform suspension is obtained.     -   2. Add all other ingredients excluding polymers and heat to         75° C. to melt and dissolve and obtain homogeneous mixture.     -   3. Mix well and cool to below 40° C. and add the polymers and         sensitive ingredients with moderate mixing.     -   4. Cool to room temperature.     -   5. In case of polymers dissolved in water or organic solvent,         dissolve the polymers in the solvent with heating or cooling as         appropriate for specific polymer and add to the oily mixture         under vigorous mixing at ˜40° C.

Canisters Filling and Crimping

Each aerosol canister is filled with PFF and crimped with valve using vacuum crimping machine.

Pressurizing

Propellant Filling

Pressurizing is carried out using a hydrocarbon gas or gas mixture

Canisters are filled and then warmed for 30 sec in a warm bath at 50° C. and well shaken immediately thereafter.

Closure Integrity Test.

Each pressurized canister is subjected to bubble and crimping integrity testing by immersing the canister in a 60° C. water bath for 2 minutes.

Canisters are observed for leakage as determined by the generation of bubbles. Canisters releasing bubbles are rejected.

Tests

By way of non limiting example the objectives of hardness, collapse time, viscosity, bubble size, nano size and FTC stability tests are briefly set out below as would be appreciated by a person of the art.

Hardness

LFRA100 instrument is used to characterize hardness. A probe is inserted into the test material. The resistance of the material to compression is measured by a calibrated load cell and reported in units of grams on the texture analyzer instrument display. Preferably at least three repeat tests are made. The textural characteristics of a dispensed foam can effect the degree of dermal penetration, efficacy, spreadability and acceptability to the user. The results can also be looked at as an indicator of softness. Note: the foam sample is dispensed into an aluminum sample holder and filled to the top of the holder.

Collapse Time

Collapse time (CT) is examined by dispensing a given quantity of foam and photographing sequentially its appearance with time during incubation at 36° C. It is useful for evaluating foam products, which maintain structural stability at skin temperature for at least 1 min.

Viscosity

Viscosity is measured with Brookfield LVDV-II+PRO with spindle SC4-25 at ambient temperature and 10, 5 and 1 RPM. Viscosity is usually measured at 10 RPM. However, at about the apparent upper limit for the spindle of ˜>50,000 CP, the viscosity at 1 RPM may be measured, although the figures are of a higher magnitude. Unless otherwise stated viscosity of the pre foam formulation is provided.

FTC (Freeze Thaw Cycles)

To check the foam appearance under extreme conditions of repeated cycles of cooling, heating, (first cycle) cooling, heating (second cycle) etc., commencing with −10° C. (24 hours) followed by +40° C. (24 hours) measuring the appearance and again repeating the cycle for up to four times.

Creaming by Centrifugation:

-   -   1. Principle of test         -   The centrifugation used in this procedure serves as a stress             condition simulating the aging of the liquid dispersion             under investigation. Under these conditions, the centrifugal             force applied facilitates the coalescence of dispersed             globules or sedimentation of dispersed solids, resulting in             loss of the desired properties of the formulated dispersion.     -   2. Procedure         -   2.1. Following preparation of the experimental             formulation/s, allow to stand at room temperature for 24 h.         -   2.2. Handle pentane in the chemical hood. Add to each             experimental formulation in a 20-mL glass vial a quantity of             pentane equivalent to the specified quantity of propellant             for that formulation, mix and allow formulation to stand for             at least 1 h and not more than 24 h.         -   2.3. Transfer each mixture to 1.5 mL microtubes. Tap each             microtube on the table surface to remove entrapped air             bubbles.         -   2.4. Place visually balanced microtubes in the centrifuge             rotor and operate the centrifuge at one or more of 10,000             rpm for 10 min, 3,000 rpm for 10 min or at 1,000 rpm for 10             min.

Bubble Size:

Foams are made of gas bubbles entrapped in liquid. The bubble size and distribution reflects in the visual texture and smoothness of the foam. Foam bubbles size is determined by dispensing a foam sample on a glass slide, taking a picture of the foam surface with a digital camera equipped with a macro lens. The diameter of about 30 bubbles is measured manually relatively to calibration standard template. Statistical parameters such as mean bubble diameter, standard deviation and quartiles are then determined. Measuring diameter may also be undertaken with image analysis software. The camera used was a Nikon D40X Camera (resolution 10 MP) equipped with Sigma Macro Lens (ref: APO MACRO 150 mm F2.8 EX DG HSM). Pictures obtained are cropped to keep a squared region of 400 pixels×400 pixels.

Nano Size:

The light microscope enables observing and measuring particles from few millimeters down to one micron. Light microscope is limited by the visible light wavelength and therefore is useful to measuring size of particles above 800 nanometers and practically from 1 micron (1,000 nanometers). Measuring smaller particle, nano size range, is performed by a Dynamic light scattering (DLS), sometimes referred to as Photon Correlation Spectroscopy (PCS) or Quasi-Elastic Light Scattering (QELS). The method is a non-invasive, well-established technique for measuring the size of molecules and particles typically in the sub micron region, and with the latest technology lower than 1 nanometer. Measurements are usually made without a vacuum, but wherever appropriate a vacuum can be applied. A Malvern nano sizeris SB-A-018 nano zs Serial num: MAL 50041 for example may be used.

EXAMPLES

The following examples exemplify the compositions and methods described herein. The examples are for the purposes of illustration only and are not intended to be limiting. Many variations will suggest themselves and are within the full intended scope of the appended claims.

Example 1 SME-Based Foamable Composition 1. Emulsion Formula

% w/w A Mineral oil (oil) 5.60 Isopropyl myristate (emollient) 5.60 Glyceryl monostearate (emollient) 0.45 PEG-40 Stearate (surfactant) 2.60 Stearyl alcohol (foam adjuvant) 0.85 B Xanthan gum (gelling agent) 0.26 Methocel K100M (gelling agent) 0.26 Polysorbate 80 (surfactant) 0.90 Water 74.88 C Preservative 0.60 D Propellant 8.00 100.00

2. Emulsion Preparation

Oil Phase (A): The ingredients of the Oil Phase were preheated to the same temperature, e.g., 40-75° C., and then were combined with mixing. Oil soluble cosmetic or pharmaceutical active ingredients and optional oil soluble formulation ingredients are added with agitation to the Oil Phase mixture.

Aqueous Phase (B): Water gelling agent and surfactant were dissolved in water, with agitation. The solution was warmed to 50-70° C. Water soluble cosmetic or pharmaceutical active ingredients and optional water soluble ingredients were added with agitation to the Aqueous Phase mixture.

The warm Oil Phase was gradually poured into the warm Aqueous Phase, with agitation, followed by Ultraturax homogenization. The mixture was allowed to cool down to ambient temperature. In case of heat sensitive active ingredients, the active ingredient can be added with agitation to the mixture after cooling to ambient temperature. The mixture, at ambient temperature, was added to an aerosol container, the container was sealed and appropriate amount of propellant (5-25 w % of the composition mass) was added under pressure into the container.

Microscopic observation of the resulting emulsion revealed mean particle size of 2 to 4 microns.

3. Conversion of the Emulsion to Nanoemulsion (Pre-Foam Composition)

The emulsion was passed through a microfluidizer, Microfluidics M-110Y Microfluidizer® M-110Y about 10 cycles, using ice to avoid heating the formula.

4. Packaging and Pressurizing of the Nanoemulsion Composition

A nanoemulsion composition (46 gram) was introduced into a 60 ml monoblock aluminum can. The can was sealed with an aerosol valve and 4 gram of liquefied propellant (propane butane isobutene mixture) was added through the valve.

5. Characterization of the Nano Emulsion

Particle size distribution was determined using a Malvern Nanosizer™ instrument. The pre-foam composition showed two peaks of 188 and 59 nanometers. Four days after packaging and pressurizing of the composition, foam was released from the aerosol can and light microscope observation revealed small population of ˜1 micron globules and substantial Brownian movement indicating that majority of oil droplets are of sub-micron or nano-scale.

6. Packaging and Pressurizing of the Nano Emulsion Composition

An emulsion (46 gram) was added into a 60 ml monoblock aluminum can. The can was closed with an aerosol valve and 4 gram of liquefied propellant (propane/butane mix) was added through the valve. The propellant can be any compressed and liquefied gas, currently used as aerosol propellant. The final concentration of propellant can vary from 3% to 25%.

Example 2 Oil Bodies Based Foamable Compositions

NAT01 NAT02 NAT03 NAT04 % w/w % w/w % w/w % w/w Natural Oleosomes 30.00 30.00 30.00 30.00 (Natrulon OSF)* Hydroxypropylmethycellulose 0.25 0.25 — — (gelling agent) Xanthan Gum (gelling agent) 0.25 0.25 — — Cocamide DEA (surfactant) 1.00 1.00 Polsorbate 20 (surfactant) — — — 1.00 Water pure 68.50 69.50 69.00 69.00 100.00 100.00 100.00 100.00 Foam Properties Foam Quality E E E G Stability RT Stable Stable Creaming Creaming After After 72 Hr. 72 Hr. *Natrulon OSF is the trade name of Lonza Inc.

The production of the compositions NATO1 included the following steps:

-   -   1. Add the polymeric agents (Hydroxypropylmethycellulose and         Xanthan Gum) to the Natrulon OSF at 50° C. and mix during 10         minutes while the preparation cools down to Room Temperature.     -   2. Add the Cocamide DEA with mixing.     -   3. Fill the composition aerosol canisters and add 8% of         propellant.

The production of the compositions NATO2 included the following steps:

-   -   1. Add the polymeric agents (Hydroxypropylmethycellulose and         Xanthan Gum) to the Natrulon OSF at 50° C. and mix during 10         minutes while the preparation cools down to Room Temperature.     -   2. Fill the composition aerosol canisters and add 8% of         propellant.

The production of the compositions of NATO3 included the following steps:

-   -   1. Add the cool water to the Natrulon OSF and mix during 10         minutes.     -   2. Add the Cocamide DEA with mixing.     -   3. Fill the composition aerosol canisters and add 8% of         propellant.

The production of the compositions of NATO4 included the following steps:

-   -   1. Add the cool water to the Natrulon OSF and mix during 10         minutes.     -   2. Add Polysorbate 20 with mixing.     -   3. Fill the composition aerosol canisters and add 8% of         propellant.

Example 3 Further Foamable Compositions Containing Oil Bodies

% w/w % w/w Caprylic/capric triglyceride (MCT oil) 5.00 — Stearyl alcohol 0.90 — Natrulon OSF* 10.00 10.00 Methylcellulose 0.25 0.25 Xanthan gum 0.25 0.25 PEG-40 stearate 2.50 2.50 Polysorbate 80 0.90 0.90 Preservative 0.50 0.50 Purified water to 100% to 100% Propellant 8.00

Formation Properties

Emulsion visual test Uniform Uniform Viscosity (Spindle SC4-31)(cP) 1,428 868.5 Centrifugation (prior to propellant addition) Stable Stable (10 min/3,000 rpm) PH (direct, prior to propellant addition) 6.04 6.72 Foam Quality G E Density 0.0337 0.0339

Example 4 Exploring Some Limitations on Making Nano-Emulsions

Ingredients NEP002 NEP006 Isopropyl myristate 6.00 6.00 light Mineral oil 6.00 6.00 Glyceryl 0.50 1.00 monostearate PEG-40 stearate 3.00 6.00 Stearyl alcohol 1.00 1.00 Xanthan gum 0.30 0.30 Methocel K100M 0.30 0.30 Polysorbate 80 1.00 2.00 Water, purified 81.30 76.80 Sharomix 824 0.60 0.60 Total 100.00 100.00 Propellant 8.00 8.00 Cycles 4 3 Pressure (Bar) 1000-1500 Comments inter alia Emulsion broke Emulsion still as to non suitability after first cycle broke after first for nano emulsion cycle with double preparation surfactant that of 002. Comment: None of the above two formulations were found suitable for preparation of a nano emulsion using a high pressure homogenizer. This indicates that the selection of surfactants that can hold the emulsion together whilst being subject to the effects of being processed in a high speed homogenizer is of importance in the preparation of nano emulsions. Formulations were also prepared with a combination of high and medium levels of petrolatum and mineral oil (42% and 18% respectively) and with medium levels of petrolatum (25%). In both cases the formulation was found to be too viscous to be used with the nano emulsion. None of the above formulations were found suitable for preparation of a nano emulsion using a high pressure homogenizer primarily because of their high viscosity. Nevertheless, it is believed that the issue of viscosity may be overcome-able by warming the formulation and or reducing the levels of petrolatum. A formulation containing a powder suspension was also found to be unsuitable due to sedimentation. Accordingly, to the extent a formulation is to comprise a suspension that element may be introduced after a stable nano emulsion carrier is produced rather than during the process. For satisfactory processing the emulsion should have sufficient stability to withstand gentle heating.

Example 5 Behavior of Stable Homogeneous Emulsions with Two Different Oils

Ingredients NEP007 NEP008 Diisopropyl adipate (DISPA) 20.00 PPG 15 Stearyl ether (PPG) 20.00 Steareth-2 3.67 4.00 Steareth 21 2.33 1.00 Carboxy methyl cellulose 0.50 0.50 Water, purified 72.90 73.90 Sharomix 824 0.60 0.60 Total 100.00 100.00 Propellant 8.00 8.00 Cycles 5 6 Pressure (Bar) 1000-1500 1000-1500 Visual Inspection Homogeneous Homogeneous Shakability Yes Yes F.Q. Good Fairly Good Cetrif: 3000 RPM Stable Stable Cetrif: 10000 RPM 30% 90% Creaming Creaming Density 0.057 N/R Viscosity(cP) 10 RPM 4734.99 3775.19 Collapse Time (sec.) >300 >300 PFF Size Study: Diameter (nm)/% volume- 25 C. 718/92.4% 2590/86.8% 147/7.6%* 243/13.2* Dilution 1:80 w/w with 1:80 w/w with vacuum vacuum FOAM Size Study: Diameter (nm)/% volume- 25 C. 2790/82.4% 328/17.6% Dilution 1:80 w/w with 1:80 w/w with vacuum* vacuum* *-example of *-example of results results achieved achieved FTC (4 cycles) Quality Good Density 0.046 Collapse time (sec.) >300 >300 1 Month 40 C. Quality Excellent Fairly Good Density 0.045 Collapse time (sec.) >300 Diameter (nm)/% volume- 25 C. 3410/100% Dilution 1:80 w/w with vacuum* Comment: After 5 or 6 cycles of high pressure homogenization the emulsion appears to behave differently depending on which oil is used. In the presence of 20% DISPA a good quality foam is produced containing large nano particles primarily in the region of 700 nanometers and which can withstand four freeze thaw cycles (FTC) but which reverts to form globules of over 3 microns after a month. In contrast in the presence of 20% PPG foam quality is fairly good and the oil droplets have a diameter primarily in the region of 2600 nanometers or 2.6 microns.

Example 6 Production of Stable Homogeneous Emulsions with Petrolatum

Ingredients NEP010 White Petrolatum (sofmetic) 7.14 Steareth-2 1.43 Steareth 21 4.29 Carboxy methyl cellulose 0.36 Water, purified 86.18 TEA, q.s. to pH: to pH 4.77 Sharomix 824 0.60 Total 100.00 Propellant 8.00 Cycles 6 Pressure (Bar) 1000-1500 Visual Inspection Homogeneous Shakability Yes F.Q. Excellent* Cetrif: 3000 RPM Stable Cetrif: 10000 RPM 98% translucent Viscosity (cP) 10 RPM 7.00 Collapse Time (sec.) >300 PFF Size Study: Diameter (nm)/% volume- 25 C. 125/100% Dilution 1:10 v/v FOAM Size Study: Diameter (nm)/% volume- 25 C. 275/22.1% 96.8/16.1% 26.2/55.4% Dilution 1:10 w/w *After 2 weeks FG FTC (4 cycles) Quality Good Density 0.036 Collapse Time (sec.) >300 Comment: Petrolatum produces formulations with higher viscosity as it is a viscous material. Nevertheless, by reducing the content of petrolatum and by gentle warming it is possible to make nano emulsions with petrolatum. Not only was the above formula homogenous and stable to centrifugation but it produced foam of excellent quality having pre foam nano particles size primarily in the region of 125 nanometers and the majority of the foam nano particles being in the region of 26 nanometers. Remarkably, the formulation viscosity showed a dramatic reduction. Without being bound by any theory this may be connected to the high pressure mechanical manipulation of petrolatum and possible breakdown of polymer and further it seems that there can be a close connection between reduction of viscosity and successful smaller nano emulsion formulations. On the other hand by using a different polymer carbomer an acrylic polymer it was possible to achieve a successful larger nano emulsion with high viscosity that remained stable for a month at 40 C; stable to centrifugation and stable to FTC as can be seen in Formula 12 Example 8

Example 7 Examination of Number of Cycles

NEP011-4C NEP011-6C Isopropyl myristate 5.00 5.00 Octyl dodecanol 5.00 5.00 Cetearyl alcohol 3.00 3.00 Polyoxyl 100 monostearate 2.50 2.50 Methocel K100 LV 0.20 0.20 Carbomer 934P 0.40 0.40 Polysorbate 80 0.50 0.50 Propylene glycol 3.34 3.34 Water, purified 79.81 79.81 TEA, q.s. to pH: to pH 4.60 to pH 4.70 Propyl Paraben 0.10 0.10 Methyl paraben 0.15 0.15 Total 100.00 100.00 Propellant 8.00 8.00 Cycles 4 6 Pressure (Bar) 1000-1500 1000-1500 Visual Inspection Homogenous Homogenous Shakability Yes Yes F.Q. Excellent Excellent Cetrif: 3000 RPM Stable Stable Cetrif: 10000 RPM Stable Stable Density 0.041 Viscosity (cP) 10 RPM 5198.89 52.99 Collapse Time (sec.) >300 PFF Size Study: * Diameter (nm)/% volume- 25° C. 570/100% 251/100% Dilution 1:80 w/w 1:80 w/w FOAM Size Study: Diameter (nm)/% volume- 25 C. 667/85.2% 297/100% 99.1/4% 5220/10.4% Dilution 1:80 w/w 1:80 w/w FTC (4 cycles) Quality Excellent Density 0.038 * Separation after 5 days, reversible Comment: The question of how many cycles are preferable was examined. Using too few cycles may not produce emulsions with oil droplets in the lower nanometer range. On the other hand there is some concern that using too many cycles may destroy the ability to make good quality stable homogenous nano foam. Nano emulsions are fragile and metastable. Much energy work is required to reduce oil droplets size. The energy is invested in creating large interfacial area between the two immiscible phases. At first the energy input contributes to creation of the interfacial area and particle size reduction. At some point, an extra energy does not contribute any more to size reduction and instead causes particle collapse, increases in particle size and reduction in interfacial area. Every process of emulsification and energy input has an optimum which will be related for example to formulation, mean of energy input, homogenization and other criteria. It was noted that in general three cycles was insufficient and that signs of nano emulsion qualities of translucent foam with a blue tint became more recognizable from four cycles. Thus a study was made to compare four with six cycles. It can be seen that after four cycles the pre foam formulation had a nano size primarily in the region of 570 nanometers and a reasonable viscosity in the range of 5000 Cp. However, when the processing was extended to six cycles there was a remarkable reduction in viscosity of about a hundred fold to the range of 50 cP and that the nano size of the pre foam formulation was halved. Interestingly, when foam was produced the nano size was substantially the same, suggesting that conversion to foam does not disturb the nano particle size to any significant extent. On the other hand as can be seen below there a dramatic effect on bubble size is observed between a pre and post nano processed formulation. Also of note is the observation that dramatic reduction in viscosity is seen with the polymeric combination of methocel and carbomer. However, as seen in Example 8 below, when the polymeric agent is only pH adjusted carbomer the formulation remains with high viscosity after 6 cycles

Example 8 Behavior of Stable Homogeneous Emulsions with a Third Different Oil

Ingredients NEP012 Isopropyl myristate 20.00 Steareth-2 4.34 Steareth 21 2.66 Carbomer 934P 0.50 Propylene glycol 3.00 Water, purified 69.00 TEA, q.s. to pH: to pH 4.66 Sharomix 824 0.50 Total 100.00 Propellant 8.00 Cycles 6 Pressure (Bar) 1000-1500 Visual Inspection Homogenous Shakability Yes F.Q. Excellent Centrifugation: 3000 RPM Stable Centrifugation: 10000 RPM Stable Density 0.065 Viscosity (cP) 10 RPM 21595.39 Collapse Time (sec.) >300 PFF Size Study: Diameter (nm)/% volume- 25° C. 802/100% Dilution 1:80 w/w FOAM Size Study: Diameter (nm)/% volume- 25° C. 688/90.8% 5240/7.3% 110/1.8% Dilution 1:80 w/w FTC Quality Excellent Density 0.073 Collapse Time (sec.) >300 1 month 40 C. Quality Excellent Density 0.048 Collapse Time (sec.) >300 Diameter (nm)/% volume- 25 C. 831//71.4% 154/3.3% 5040/25.3% Dilution 1:80 w/w Comment: Like the formulations discussed in Example 5, this example is based on 20% oil. The oil is isopropyl myristate, which is a third type of oil. Here the formula was pH adjusted with triethanolamine (TEA). The oil droplet size for the pre-foam formulation was of the order of 800 nanometers and that of the foam was of the order of 700 namometers indicating that isopropyl myristate is not dissimilar from DISPA in relation to the size of resultant nano particles. Moreover, after a month at 40 C most of the globules were of the order 830 nanometers. Of the three formulations isopropyl myristate, made the best quality foam, which likewise may more suit nano emulsion preparation albeit at the higher end of the scale. The viscosity of the pre foam formulation is high primarily due to the level of carbomer and the pH. At this viscosity the composition is flowable but not really shakable. However, upon addition of propellant the formulation is shakable.

Example 9 Examination of Effects of Reducing/Increasing Surfactant Levels

NEP013 NEP015 NEP014 Isopropyl myristate 10.00 10.00 10.00 light Mineral oil 10.00 10.00 10.00 Glyceryl monostearate 0.50 0.50 0.50 PEG-40 stearate 3.20 2.40 1.60 Stearyl alcohol 1.50 1.50 1.50 Carbomer 934P 0.40 0.40 0.40 Polysorbate 80 4.80 3.60 2.4 Propylene glycol 3.00 3.00 3.00 Water, purified 66.00 68.00 70.10 TEA, q.s. to pH: to pH 4.66 to pH 4.71 to pH 4.60 Sharomix 824 0.60 0.60 0.50 Total 100.00 100.00 100.00 Propellant 8.00 8.00 8.00 Cycles 6 6 6 Presion (Bar) 11000-1500 11000-1500 1000-1500 Visual Inspection Homogenous Homogenous Homogenous (highly translucent) Shakability Yes Yes Yes F.Q. Excellent Excellent Excellent Centrifugation: Stable Stable Stable 3000 RPM Centrifugation: Stable Stable Stable 10000 RPM Density 0.052 0.045 10.042 Viscosity (cP) 10 RPM 241.95 207.96 107.96 Collapse Time (sec.) >300 >300 >300 PFF Size Study: Diameter (nm)/ 80.2/100% 105/100% 149/100% % volume- 25 C. Dilution 1:15 v/v 1:20 v/v 1:20 v/v FOAM Size Study: Diameter (nm)/ 104 nm/88.7%, 120/88.2% 179/84.8 % volume- 25 C. 4660 nm/11.3% 4740/11.8% 5280/15.2% Dilution 1:15 w/w 1:20 w/w 1:20 w/w with vacuum FTC Quality Good Density 0.050 Collapse Time (sec.) >300 Diameter (nm)/ 117/62.1% % volume- 25 C. 822/8% 3400/29.9% 1-Month 40 C. Quality Good Density 0.045 Collapse Time (sec.) >300 Diameter (nm)/ 72.8/76.3% % volume- 25 C. 3290/23.7% Dilution 1:15 w/w Comment: The surfactant concentrations of PEG-40 stearate and Polysorbate 80 were decreased from 8% to 6% to 4% to examine the effect of surfactant levels on nano sizing of the formulations and foam. Whilst all the formulations produced foam of excellent quality there was a clear and consistant effect on oil droplet size. As the level of surfactant was reduced there was a corresponding increase in nano size. Thus higher levels of surfactant support a lower nano size. Approximately parallel reductions were also observed in viscosity and in density as the surfactant levels were reduced. It is also noteworthy that after a month at 40 C the globules size remained substantially the same

Example 10 A Comparison of Bubble Size of Resultant Foam Before and after Processing the Formulation to Produce a Nano Composition

Notes to FIGS. 1A through 5C:

-   -   C0 means the formulation was not subject to nano processing.     -   C6 means the formulation was subject to 6 cycles of nano         processing.     -   AP 70 and AP 46 are propellants comprising similar mixtures of         propane, butane and isobutane but the former offers about 50%         more pressure.

In all cases observed as shown in FIGS. 1A through 5C, nano emulsions surprisingly produced foam with a substantially larger foam bubble size ranging from an increase of about a third to an increase of almost four fold in magnitude, when the identical same formulation was subject to nano processing. Thus, by creating a nano emulsion it is possible to generate foam of quality with a larger bubble size, which may intern positively influence the cosmetic elegance of the foam in that the formulation may have a more foam like feel with less of the sensation and greasy feeling that might be experienced with a cream or mousse Also, the increased bubble size may contribute to ease of spreadability. It was also discovered that it is possible to manipulate bubble size by propellant selection. So for example, bubble size was seen to increase by about a third when a higher pressure hydrocarbon propellant was substituted in the same formulation

Example 11 A Comparison of Physical Properties of Resultant Foam Before and after Processing (Six Cycles) the Formulation to Produce a Nano Composition Part A

NEP 010 Regular, C-0 Nano, C-6 PFF Centrifugation: 3000 RPM Stable Stable Centrifugation: 60% Creaming 98% translucent 10000 RPM Visual Inspection Homogenous, Homogenous, opaque-liquid Translucent Viscosity (cP) 10 RPM 686.85 7.00 Oil droplets size <4 micrometer 125 Nanometers/100% Foam Quality FG after 24 Hrs Excellent (FG after 2 Weeks) Shakability Yes Yes Collapse time (sec.) >300 Oil droplets size <4 micrometer 275/22.1%; 96.8/16.1% 26.2/55.4%

Part B

NEP011 Regular, C-0 Nano, C-6 PFF Centrifugation: Stable Stable 3000 RPM Centrifugation: 95% Creaming Stable 10000 RPM Visual Inspection Homogenous, Homogenous, viscose Translucent Viscosity (cP) 10 RPM 36872.13 52.99 Oily droplets size Diameter 4-14 251 Nanometers/ micrometers 100% Foam Quality Excellent Excellent Density 0.045 0.041 Shakability No Yes Collapse time (sec.) >300 >300 Oil droplets size >4 micrometers 297 Nanometers/ 100%

Part C

NEP 013 Regular C-0 Nano C-6 PFF Centrifugation: Stable stable 3000 RPM Centrifugation: 30% Creaming stable 10000 RPM Appearance Homogenous, Homogenous highly highly viscose translucent Viscosity (cP) 10 RPM 27178.2 241.95 Oil droplets size Diameter 4-17 80.2 Nanometers/100% micrometers Foam Quality Excellent Excellent Density 0.062 0.052 Shakability No Yes Collapse time (sec.) >300 >300 Oil droplets size Diameter 4-17 104 nm/88.7%, micrometers 4660 nm/11.3% Comment: In the above three cases formation of nano emulsions having nano size particles resulted in a substantial reduction in the formulation viscosity even though chemically the formulation constituents were unchanged. No significant change of collapse time was observed. Formulations which were non shakable prior to processing were became shakable following processing. Also remarkably formulations that produced only fairly good foam prior to processing were improved such that, for example, excellent foam may be formed. True nano emulsions appeared translucent with a blue hint whereas prior to processing the emulsions were generally opaque. 

What is claimed is:
 1. A foamable oil in water nano emulsion composition comprising: (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of i. a non-ionic surfactant, ii. an ionic surfactant, and iii. a polymeric agent; (c) water; and (d) a liquefied or compressed gas propellant at a concentration of about 3% to about 25% by weight of the total composition wherein the oil, stabilizer and water are selected to provide a composition that is substantially homogenous and resistant to aging; wherein the composition is contained in a pressurized container is substantially flowable and provides a breakable foam upon release, which is thermally stable, yet breaks under sheer force; and wherein the bubble size of the resultant foam is significantly greater than the bubble size of the resultant foam from a composition with the same ingredients which has not been subject to nano processing.
 2. The foamable composition of claim 1, wherein the oil globule system consists of oil globules with an average diameter size in the range of about 1000 nanometers to about 10 nanometers; and the stabilizing agent consists of a polymeric agent.
 3. The foamable composition of claim 2, further comprising a non-ionic surfactant having an HLB value between 9 and 16; and/or an ionic surfactant.
 4. The foamable composition of claim 1, wherein: i. the oil globule system consists of sub-micron oil globules; and ii. the stabilizing agent consists of a surfactant, having an HLB value or a mean HLB value between 9 and
 16. 5. The foamable composition of claim 1 wherein the ratio of the surfactant to oil is high being in the range of the order of about 1:1 to about 1:10
 6. The foamable composition of claim 1, wherein the sub-micron oil globules contain at least one organic carrier selected from the group consisting of a hydrophobic organic carrier, a polar solvent, an emollient and mixtures thereof.
 7. The foamable composition of claim 1, wherein said submicron oil globules are about 50% to about 100% of the composition.
 8. The foamable composition of claim 1, wherein the sub-micron oil globules have a number-average size range, selected from (i) 40 nm to 1,000 nm. (ii) 40 nm to 500 nm; (iii) 40 nm to 200 nm; (iv) 40 nm to 100 nm (v) less than 500 nm; (vi) less than 200 nm; and (vii) less than 100 nm.
 9. The foamable composition of claim 1, further comprising about 0.1% to about 5% by weight of a foam adjuvant selected from the group consisting of a fatty alcohol having 15 or more carbons in their carbon chain; a fatty acid having 16 or more carbons in their carbon chain; fatty alcohols derived from beeswax and including a mixture of alcohols, a majority of which has at least 20 carbon atoms in their carbon chain; a fatty alcohol having at least one double bond; a fatty acid having at least one double bond; a branched fatty alcohol; a branched fatty acid; and a fatty acid substituted with a hydroxyl group and mixtures thereof.
 10. The foamable composition of claim 1, wherein said foamable composition is substantially alcohol-free.
 11. The foamable composition of claim 1, further containing at least one therapeutic agent.
 12. The foamable composition of claim 11, wherein the therapeutic agent is selected from the group consisting of an anti-infective, an antibiotic, an antibacterial agent, an antifungal agent, an antiviral agent, an antiparasitic agent, an steroidal antiinflammatory agent, an immunosuppressive agent, an immunomodulator, an immunoregulating agent, a hormonal agent, vitamin A, a vitamin A derivative, vitamin B, a vitamin B derivative, vitamin C, a vitamin C derivative, vitamin D, a vitamin D derivative, vitamin E, a vitamin E derivative, vitamin F, a vitamin F derivative, vitamin K, a vitamin K derivative, a wound healing agent, a disinfectant, an anesthetic, an antiallergic agent, an alpha hydroxyl acid, lactic acid, glycolic acid, a beta-hydroxy acid, a protein, a peptide, a neuropeptide, a allergen, an immunogenic substance, a haptene, an oxidizing agent, an antioxidant, a dicarboxylic acid, azelaic acid, sebacic acid, adipic acid, fumaric acid, a retinoid, an antiproliferative agent, an anticancer agent, a photodynamic therapy agent, an anti-wrinkle agent, a radical scavenger, a metal oxide (e.g., titanium dioxide, zinc oxide, zirconium oxide, iron oxide), silicone oxide, an anti wrinkle agent, a skin whitening agent, a skin protective agent, a masking agent, an anti-wart agent, a refatting agent, a lubricating agent and mixtures thereof.
 13. The foamable composition of claim 12, wherein the therapeutic agent is suitable to treat a disorder, selected from a dermatological disorder, a cosmetic disorder, a gynecological disorder, a disorder of a body cavity, wound and burn.
 14. The foamable composition of claim 1, wherein the HLB or mean HLB value of said non-ionic surfactant is between about 2 and about
 9. 15. The foamable composition of claim 1, wherein the stabilizing agent is a polymeric agent selected from the group consisting of a water-soluble cellulose ether naturally-occurring polymeric material, microcrystalline cellulose, hydrophobically-modified ethoxylated urethane, and a carbomer and wherein said water-soluble cellulose ether is selected from the group consisting of methylcellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose (Methocel), hydroxyethyl cellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, hydroxyethylcarboxymethylcellulose, carboxymethylcellulose, carboxymethylhydroxyethylcellulose, xanthan gum, guar gum, carrageenin gum, locust bean gum and tragacanth gum.
 16. The foamable composition of claim 1, wherein surfactant is selected from the group consisting of steareth 2, steareth 21, ceteth-20, span 80, behenyl alcohol, glyceryl monostearate, PEG 40 stearate, polyoxyl 100 monostearate, methyl glucose seasquit stearate and polysorbate
 80. 17. The foamable composition of claim 1, wherein the density of the foam is selected from the group consisting of (1) less than 0.12 g/mL; (2) the range between 0.02 and 0.12; (3) the range between 0.04 and 0.10; (4) the range between 0.06 and 0.10.
 18. A foamable oil in water nano emulsion composition comprising: (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of i. a non-ionic surfactant, ii. an ionic surfactant, and iii. a polymeric agent; and (c) water; wherein the oil, stabilizer and water are selected to provide a composition that is substantially homogenous and resistant to aging; wherein the composition prior to addition of propellant is translucent with a blue tint; wherein if the composition is contained in a pressurized container and further comprises a liquefied hydrocarbon gas propellant at a concentration of about 3% to about 35% by weight of the total composition it is substantially flowable and provides a breakable foam upon release, which is thermally stable, yet breaks under sheer force; and wherein the bubble size of the resultant foam is significantly greater than the bubble size of the resultant foam from a composition with the same ingredients which has not been subject to nano processing.
 19. A method of promoting the penetration of an active agent into the surface layers of the skin and mucosal membranes, comprising: apply a foamable composition to the surface layers of a stem or mucosal membrane, the foamable composition comprising: (a) a nano oil globule system, comprising substantially of sub-micron oil globules; (b) about 0.1% to about 5% by weight of at least one stabilizing agent, selected from the group consisting of i. a non-ionic surfactant, ii. an ionic surfactant, and iii. a polymeric agent; and (c) water; wherein the oil, stabilizer and water are selected to provide a composition that is substantially homogenous and resistant to aging; wherein the composition prior to addition of propellant is translucent with a blue tint; wherein if the composition is contained in a pressurized container and further comprises a liquefied hydrocarbon gas propellant at a concentration of about 3% to about 35% by weight of the total composition it is substantially flowable and provides a breakable foam upon release, which is thermally stable, yet breaks under sheer force; and wherein the bubble size of the resultant foam is significantly greater than the bubble size of the resultant foam from a composition with the same ingredients which has not been subject to nano processing.
 20. The method of claim 19, wherein the active agent is selected from the group consisting of an anti-infective, an antibiotic, an antibacterial agent, an antifungal agent, an antiviral agent, an antiparasitic agent, an steroidal antiinflammatory agent, an immunosuppressive agent, an immunomodulator, an immunoregulating agent, a hormonal agent, vitamin A, a vitamin A derivative, vitamin B, a vitamin B derivative, vitamin C, a vitamin C derivative, vitamin D, a vitamin D derivative, vitamin E, a vitamin E derivative, vitamin F, a vitamin F derivative, vitamin K, a vitamin K derivative, a wound healing agent, a disinfectant, an anesthetic, an antiallergic agent, an alpha hydroxyl acid, lactic acid, glycolic acid, a beta-hydroxy acid, a protein, a peptide, a neuropeptide, a allergen, an immunogenic substance, a haptene, an oxidizing agent, an antioxidant, a dicarboxylic acid, azelaic acid, sebacic acid, adipic acid, fumaric acid, a retinoid, an antiproliferative agent, an anticancer agent, a photodynamic therapy agent, an anti-wrinkle agent, a radical scavenger, a metal oxide (e.g., titanium dioxide, zinc oxide, zirconium oxide, iron oxide), silicone oxide, an anti wrinkle agent, a skin whitening agent, a skin protective agent, a masking agent, an anti-wart agent and a refatting agent. 